sourcehighlight is annoyingly slow, but it does support wiki directives in comments. See here for an example (tags).

I think that is just a result of it expanding directives, and wikilinks, everywhere in the file, which is generally a possible problem.. --Joey

I think having the option to choose source code page types from the dropdown list is definitely a feature. This gives users an easy way to contribute programs (say .pl files) or code snippets (like, for example, the Elisp area of the EmacsWiki). Actually, would there any other way to create a .pl file without write access to the repository? --JasonBlevins

Well, you can upload them as an attachment if the wiki is configured to allow it. Having them in the drop down becomes a problem when there are so many wacky extensions in there that you can't find anything. --Joey

I should just note that the sourcecode plugin only adds the file extensions listed in the config. This shouldn't cause massive drop-down menu pollution. -- Will

That seems to be the way to go! --Joey