[flavor8]

Just because the blockchain is public doesn't mean that the identity of voters is public. You know which one your vote is; that information isn't otherwise public.

When you vote right now, your vote is (theoretically) tied to your identity, because every ballot has an id tied to it, so it's not like you'd be giving up any more anonymity than you had. I don't know of any practical fully anonymous election systems that are post-hoc verifiable, but maybe somebody does.