Perhaps.. but I just used their current version in CS5 yesterday.. Maybe there's some issues I haven't encountered but it seems to work fine.
One of the nice things about Ultimate.. is once you buy their USB security/licensing key (a physical USB dongle) they never seem to charge you again for upgrades. I've had mine for 7-8 years now and it still works the latest version and they've never announced an upgrade fee. Granted, $500 is a bit steep.. but for all the use I've got from the program its well worth it.