I've had to reduce my farm to 2 machines from 6 but I'm keeping them on TPU's team indefinitely. It's only about 20k WCG points per day, but it should help.
I hope I will be able to finally get a new machine up with a Powercolor 4850 up and running, but I don't know about doing any folding. I shut down the other machines because my electric bill was over $300/mo even with oil heat. I'm obsessive-compulsive but I'm not stupid - although since I'd been doing it for over a year I guess that's debatable. Anyway, I'll have to see how much the 4850 draws at load and if it interferes with video operations.
Plus, I might give some of my "old" machines to friends, in which case I'll insist they run boinc - on my account of course - hehehe.