As long as they count votes in a reasonable manner, I don't expect it to hurt. If Google can get normal people to vote up good results, the intentional spammers will never make a big enough dent to matter anyway. And even if they can't, the user votes won't make up the entire placement process, so hopefully they'd be no worse off now if they get useless results. Perhaps they can just leave it out of the mix entirely until they get a realistic-looking profile of user votes.