Something that I've noticed lately is that we have some bad tags springing up (nothing "new" there), as well as some tags that are being abused/cluttered.
Do note that this isn't a witch hunt against old questions, or even abandoned ones. This is more of a librarian just making sure that the books are in the right categories
As part of an attempt to both get a community of "edit, try again and then close if we didn't fix it", I would like to suggest (in conjunction with BlueXrider) a easy target:
Making sure some of our most popular tags are actually filled with questions that are... about that tag.
Now, I'm not saying that we need to go through all 6.3 thousand questions tagged 11.10. Far from it!
I'm thinking more along the lines of this page.
AKA, page 10 of our top tags.
Using that as a starting point is easy - we pick a tag or two, and for a week (as people have time) they go through, editing (retagging is key for some tags), answering if they can, up voting, testing answers, and if need be voting to close and flagging.
There is a chat room which can be used for communication about this - we have the regulators for closing, and then the Ask Ubuntu tag cleaners for everything else.