Well, if ya have Elements 4 at least,
this link provides one more option for getting CS4. It's still working, BTW-I used it over a week ago to get mine.
I tried a demo of Paint Shop Pro X2 (before they released their "refresh"), and while it did have a trick or two up it's sleeve, I just didn't find it compelling enough to not keep using my copy of Elements 5.
For that matter, I'm still using Elements 5 right now. CS4 is intimidating just to fire up, and while my rig can run it easily enough, I'll have to sit down with a decent hunk of time (and Scott Kelby's book when it comes out next month) and learn it first-and it took me a few weeks (and about 400 shots) just to get comfortable doing Camera Raw with Elements 5 just a couple of months ago. I personally feel that for the majority of general photography and portraiture, Elements is more than sufficient.
(So why'd I grab CS4? I want to start learning how to do higher-end portraiture and such. I'm not thinking about opening a studio or such, but I've always thought if I'm not trying to learn new techniques and such I'm not trying hard enough, and I'd need more than the 30-day demo for that sort of thing. There's a few techniques in a book that I've been perusing [
Skin by Lee Varis] that are only doable on at least CS3.)