If you go back to say Feb 2004, I think spam had gotten to be an issue because we hadn't allocated enough resources to it. Google isn't a monolith; within the company there's always room for different opinions about what different priorities should be. But I'm happy that I think Google is paying more attention to this issue now. My opinion is that spam is getting hit faster, and that for the rest of this year, it will continue to get harder to spam.
It's funny because a while ago, people would post on WebmasterWorld and say "When is Google going to pay attention to spam?" Recently I saw a post where something said "Why is Google so harsh on spam lately--why don't they work on other things besides rooting out spam?" I guess you can't please all of the people all of the time. :)