Wow, now there's a genuinely interesting idea I haven't heard before. It would prevent against patent trolls biding their time until someone profitably introduced something.
It's kind of a "put your money where your mouth is" type solution, which actually helps the little guy, too. I like it!
It doesn't help against granting stupid patents in the first place (e.g. Amazon's one click checkout), but limits their impact, I suppose.