Got the trial CS5 Extended download, installed on my Thinkpad T61p, Windows 7 Pro 64. Both 32 and 64 bit versions installed by default, only tried the 64 bit vers. Initial reactions are pretty positive - it seems nice and responsive, love the "scrubby zoom" feature. I tried the CS4 trial and passed on it, the Open GL stuff seemed sluggish but that's gone away now. I'll upgrade to this from my CS3, there's enough features to make it worthwhile. Don't use lots of plugins except for Photokit Sharpener, so I don't have those anxieties.
Adobe seem to be in, "we're gonna take over the world" mode at the moment with much of their CS Suite stuff.