I fail to see how the bleed is a big deal for the spy. Both of the bleed weapons so far have the downside of not being able to flat-out oneshot a spy with a crit, due to the Shiv's lowered damage and the Southern Hospitality's lack of crits. Besides, if the Spy is getting thwacked, he's probably dead already. The bleed just makes it slightly harder for him to get way, but not impossible. Also, why is the Spy fucking around with getting hit by Engineers and Snipers, his two main targets? If he's not destroying them outright before getting hit with whatever new bleed toy they pick up, he's doing it wrong anyway.
I had a fairly awesome time as Spy on Coldfront yesterday, mainly because there's 3 paths that a spy can take to get into position. Basically, I'd just alternate between Demoman, Pyro, and Engineer disguises, then roll up on medics, wrangler engies (WRANGER MAKES YOU HUGE SPY BAIT, JUST SAYIN), heavies, snipers, pretty much anything I could get my knife on. Ended up getting 2 or 3 kills per life with no trouble at all. It was pretty sweet.