I'm doing both...maybe.
I'm trying out iWork right now, mainly to use Numbers (I keep my budget on there). I really have no need for Word, or Pages, or PowerPoint, or Keynote, right now (I did, a lot, in college) but that could change later on. I'd like to be able to use it for work, but we have to keep all that stuff on our work computers, which bites.
One question though. As of now, I'm not too keen on iLife '08. Really, I use iPhoto '06 and nothing else, and as of now, it's just to organize my photos, not to edit them. I may upgrade later on, if my needs change, but, would I be able to upgrade to Leopard on my MacBook and install iLife '06 from my restore DVDs (or whatever's in that envelope, I didn't look at it)?