Possible phase 2:

Do something with questions with score <= 0, no accepted answer and no answers with score >= 0 after three months

If I did my query right, this is about 44,000 questions, which seems like too high to me (as in, not an accurate count.  Are things really that bad?).

http://odata.stackexchange.com/stackoverflow/s/609/qs-with-no-as-0-after-three-months

This query will let you browse the affected questions that actually have answers so you can judge what sort of treatment they need: http://odata.stackexchange.com/stackoverflow/s/610/view-deadweight-phase-2-questions

These questions could simply be removed from the Unanswered tab into a new status called "Expired".  Wouldn't need it's own tab, questions could just be accessable by searching.