Too bad I can't program myself :(Then you should be glad that xwiki is made so that even non developers can create small applications relatively easily. In addition if you're interested in contributing there are lots of ways of doing so as explained on http://dev.xwiki.org/xwiki/bin/view/Community/Contributing. One way that really helps is in helping with the documentation on xwiki.org.
As soon as I'm more familiar with xwiki, I'll certainly do that.
Thanks for the fast and detailed answer!
Simon
PS: I know developers like mailinglists, but as a user I personally would prefer a forum... ;)