1. Identification of patents
2. Delineation of the harm each patent had done
3. A central point for reporting/tracking prior art
4. A central forum for discussion and tracking of busting
You could have a kind of automagical PDF report generated on the fly for each patent, suitable for framing or providing the EFF or whatever. It would also be interesting to look at some kind of ontology for prior art. But the main thing would be to have a central place to track and discuss each patent, plus an RSS feed for patent abuse news.
I still can't believe this doesn't already exist.
Note: no business model on this except, possibly, geek-oriented advertising. (And we all know how effective that is this year.)