If you plan to accept Bitcoins without checking user identity then I think you'd quickly find yourself dealing with a lot of problems. The Bitcoin history being what it is I think anonymous payments for AWS would very quickly get used as a platform for "bad stuff", even if just anonymous proxies for doing hacks and such. I know they have other ways to do these things but it would "lower the bar" and make it more accessible.

Anyway, I use EC2 and would be interested as well... it would depend on the cut you take. And on privacy as I shouldn't have to share my access keys with you - again, given the history here that would just be silly of me.