This is a laundry list of things to think about, plan for, and/or do. Expand any significant points below into their own topics, as necessary, and link to them from here.
Static HTML distribution - use wget with link rewriting? Probably inadequate, leaving content editing links in place and not able to rewrite links in all file formats.
Note: some of this inadequacy could be addressed with a TWiki skin, which can be used to eliminate the editing links. Try appending ?skin=plain to a topic url to see an example. Custom skins are also possible - the Cookbook site uses a non-standard skin called VoidSkin, for example.
Source code distribution - see Source code management above. Can fairly trivially zip up contents of Scm web to make a source distribution. Only works if all significant source code snippets are actually stored there. See IncludingSourceCode.
(done) The login box suggests that pressing cancel will take one to the registration page. Instead one is taken to a 404 page. This has been corrected.