I'll start by saying that it doesn't matter to me where it's hosted. It took me no more time to check it out and start playing with it then if it were on github. It's DVCS, that's the important part. So I'd say choose what you think is best for you.

For completeness, the Github wiki does support Creole. In fact, it supports every major lightweight markup language thanks to the github-markup and github-gollum template abstraction libraries (markup is the library, gollum is the editor). You just select your markup in the menu above the upper right hand corner of the text area when you are editing.

I agree, though, that the guides should be hosted on a separate site to bring them all together. That's a problem we haven't yet completely solved...but that shouldn't get in the way of writing up the tutorials. Moving information around is far easier than writing it

Btw, the wiki is looking good!!! I can't wait to dive into it! For the audience, here's the link:

https://bitbucket.org/VineetReynolds/java-ee-6-galleria/wiki/Home

My initial statement needs to be updated, you do have a tutorial in progress. So it's us that could contribute to your effort

Here's an example of the Creole markup in a Github wiki page (a gist and a repo wiki use the same editor):

https://gist.github.com/2b4b485b5d5751017bdf

Note that Github does not support syntax highlighting in any markup language other than Markdown. There's an open ticket for that.

Markus Eisele has done part one of a write-up about this example on his blog.

I was very pleased to stumble over a more complex example done by Vineet Reynolds. It's called "Java EE 6 Galleria" and you can download the source code from bitbucket.