About unordered lists and bold: a line starting with ** (including optional whitespace before and afterwards), immediately following an unordered list element a line above, will be treated as a nested unordered list element. Otherwise it will be treated as the beginning of bold text. Also note that bold and/or italics cannot span lines in a list.

I think it's ugly and complicates the parser needlessly. Also, many wikis already have very similar list markup, just without this special case -- making them accept both Creole and native markup at the same time would require some sort of a hack (I can't even imagine it currently). One possible way of getting rid of that special case and still keeping list markup unambigous with bold markup is requiring a space after the bullet.

Advantages to NOT requiring space after bullet

• no opportunity for mistakes
  • since both space and no space are interpreted the same, the user doesn't need to remember to put the space
• compact text
  • list items without the space after them take up less horizontal space in the text area
  • long urls in lists may invoke a wrapping bug, leaving the bullet alone on a line -- with the line wrapped at the space immediately after the bullet
  • less keystrokes are required to type list items
  • it is faster to convert a collection of paragraphs into a list by just putting a single asterisk in front of every paragraph
• "smart" behavior
  • the right decisions for users in most common cases
  • users will be impressed with the system
• already exists
  • this is the behavior defined for Creole so far
  • this is implemented in some of the Creole parsers

Advantages to requiring space after bullet

• looks better
  • nice-looking interface means better emotional response of the users and perceived "friendliness"
  • additional space provides for easy scanning of text, making it more readable
  • because of technological deficiencies of wikis, users need to find the place they wanted to edit in the raw text; spacing marks the structure of the document visually
• is simple
  • the ambiguities with other markup are solved once and for all
  • the rule is very simple to explain, making Creole easier to teach
  • the rule can be easily observed by the users, making Creole easier to learn
  • Creole is easier to design and maintain with less special cases
• is local
  • the result of formatting depends only on the line's content itself, not on the context in which the line appears
  • the text can be easily moved around, copied and pasted
  • users don't need to scroll the text area to make sure what the formatting does
  • the markup that worked before in one case will also work the same in other cases
  • parsers can be tested and debugged more easily, as there is less interaction of different rules
• is traditional
  • it is a well established tradition, coming from the era of typewriters, to put a space after the bullet; this tradition is carried over to text files on computers
  • it is even older tradition in typography to put lead after (to the right of) punctuation characters like periods, colons, dashes or bullets
  • the space appears there anyways when rendered using practically any text rendering mechanism popular in wikis -- be it HTML, XHTML, docbook, LaTeX or texinfo.
• is user friendly
  • users make less mistakes with simple rules
  • allows to use single asterisks for bold, even when it is not parsed
  • introducing additional markup is easier, without a risk of introducing new conflicts and ambiguities
  • users don't need to do additional formatting of other's text to make it readable and easy to edit
  • removes unnatural restrictions from other markup -- emphasis can span lines, list items can consist of multiple lines

Also see: EnginesUsingAsterisksForListsAndBold

Visual comparsion

Without the space

0         1         2         3         4         5         6         7
01234567890123456789012345678901234567890123456789012345678901234567890123456789
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam
nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat
volutpat. 
*Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper
suscipit lobortis nisl ut aliquip ex ea commodo consequat. 
*Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse
molestie consequat, vel illum dolore eu feugiat nulla facilisis at
vero eros et accumsan et iusto odio dignissim qui blandit praesent
luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
*Nam liber tempor cum soluta nobis eleifend option congue nihil
imperdiet doming id quod mazim placerat facer possim assum.
*Typi non habent claritatem insitam; est usus legentis in iis qui
facit eorum claritatem. Investigationes demonstraverunt lectores
legere me lius quod ii legunt saepius.
*Claritas est etiam processus dynamicus, qui sequitur mutationem
consuetudium lectorum.

Mirum est notare quam littera gothica, quam nunc putamus parum
claram, anteposuerit litterarum formas humanitatis per seacula
quarta decima et quinta decima. Eodem modo typi, qui nunc nobis
videntur parum clari, fiant sollemnes in futurum.

With the space

0         1         2         3         4         5         6         7
01234567890123456789012345678901234567890123456789012345678901234567890123456789
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam
nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat
volutpat. 
* Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper
suscipit lobortis nisl ut aliquip ex ea commodo consequat. 
* Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse
molestie consequat, vel illum dolore eu feugiat nulla facilisis at
vero eros et accumsan et iusto odio dignissim qui blandit praesent
luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
* Nam liber tempor cum soluta nobis eleifend option congue nihil
imperdiet doming id quod mazim placerat facer possim assum.
* Typi non habent claritatem insitam; est usus legentis in iis qui
facit eorum claritatem. Investigationes demonstraverunt lectores
legere me lius quod ii legunt saepius.
* Claritas est etiam processus dynamicus, qui sequitur mutationem
consuetudium lectorum.

Mirum est notare quam littera gothica, quam nunc putamus parum
claram, anteposuerit litterarum formas humanitatis per seacula
quarta decima et quinta decima. Eodem modo typi, qui nunc nobis
videntur parum clari, fiant sollemnes in futurum.

Formatted

0         1         2         3         4         5         6         7
01234567890123456789012345678901234567890123456789012345678901234567890123456789
Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam
nonummy nibh euismod tincidunt ut laoreet dolore magna aliquam erat
volutpat. 
* Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper
suscipit lobortis nisl ut aliquip ex ea commodo consequat. 
* Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse
molestie consequat, vel illum dolore eu feugiat nulla facilisis at
  vero eros et accumsan et iusto odio dignissim qui blandit praesent
luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
* Nam liber tempor cum soluta nobis eleifend option congue nihil
imperdiet doming id quod mazim placerat facer possim assum.
* Typi non habent claritatem insitam; est usus legentis in iis qui
facit eorum claritatem. Investigationes demonstraverunt lectores
  legere me lius quod ii legunt saepius.
* Claritas est etiam processus dynamicus, qui sequitur mutationem
consuetudium lectorum.

Mirum est notare quam littera gothica, quam nunc putamus parum
claram, anteposuerit litterarum formas humanitatis per seacula
quarta decima et quinta decima. Eodem modo typi, qui nunc nobis
videntur parum clari, fiant sollemnes in futurum.