It's probably worth mentioning that anyone who wants to try FM11 or TCS4 can download it and do so. It's a fully featured, but time-bombed, install.
However, don't do it on a machine that also has installed any other version of FM, Acrobat, and for TCS4; Illustrator, RH or any other TC component. The demo install is apt to wreck the older versions, requiring a complete uninstall and re-install, assuming you have the old media, keys, etc.
Yes, if you're on Win7/64 Pro, Ult or Ent, you could install the demo in XP Mode, but be sure that:
You can (CPU has Virtualization, and you're not on Win not-so-Premium or below), and
You are willing to pay the XPM penalty (loss of 1GB RAM for starters).
I remember a discussion about that - I think you can still keep your PS install when upgrading to TCS4 (haven't tested it out yet)
I'm in the fortunate postion of having both TCS 3, and Creative Suite Std 5.5, so it doesn't worry me as much as it might. When I get my TCS 4 upgrade I might lose the PS 5 in TCS 3 and reinstall PS 5.5, which I ignored when installing Creative Suite. As long as I can keep the edit images in PS straight from FM, I'll be happy.
I don't use Illustrator that much, but I do use InDesign a bit.