Unfortunately my time machine is broken, so instead of telling what cool features are coming you have to bear with summary of what I did during the WebWorld sprint.
As you know UserBase Wiki uses the Translate extension to translate the wiki content. I can now cross off a common feature request from my todo list: moving and deleting translated pages. Since each language has its own page and the system uses even more pages behind the scenes, the normal move and delete actions of MediaWiki were insufficient. With some hackish code I was able to hijack those actions and replace them with my own. It is now possible to move or delete a page with all of its translations with few clicks. You can also choose to delete only one translation, which is useful if the translator accidentally used a wrong language.
For those who are addicted to stats, Special:LanguageStats now has a row which states the overall translation coverage. The number can be off a small amount for a reason unknown to me. I have to investigate why and fixit, since statistics never lie :)
And there is one more nicety regarding Special:MyLanguage, which takes care of redirecting users to their preferred language translation of a page, assuming such a translation exists. If the given page does not exist at all, the link using Special:MyLanguage is now red just like normal links to non-existing pages are.
The sprint itself was productive. There were problems that needed to be solved, and I think we all did a good job tackling the many issues. We also managed to create some new problems: Ingo needs to learn how to not have toys stuck in inconvenient high places :) And I like the logo very much :)