I have noticed that in the same way they have tried to route out spammers and low quality sites etc. the hardworking good webmasters get hit in the process, "casualties of war" maybe? I don't think it will stop either. As you say, spammers chop and change everything in a heartbeat, and then their back in business, No matter what Google tries, someones going to be waiting in the wings with a solution. Its the way I have seen things work.
I think, though, have you noticed that they detail their new algos? They're not the only ones with rocket scientists, if they detail what their algos do, it makes them so much easier to manipulate. Just my opinion.