I started with a 7100t, then a 7230, then a 7290, then to windows back to 7290, to 8700c, to Nokia 6620 for the past 6 months. Weird I know. I love the Nokia. I've played with the 8800 recently and the lack of the scrollwheel kills it for me. I've thought multiple times about getting the pearl for my fiancee because she'd actually like it.
The 7290 is the easiest and best to type on, but the 8800 adds so much fun stuff. If you need/want the new fun stuff I'd definitely go for it, but keep the 7290 until after the 14 day trial period.