While I prefer the 97xx series keyboard (old 8800 fan here!), the larger screen and touchscreen features of the 9800 are impossible to ignore. Personally, I'd like a mashup of the PlayBook and 9800. I'm currently using a Dell Streak <insert Android jokes/insults here> and LOVE the 5" screen and only having ONE device and cable to carry. For me, it's Lord of the Gadgets - one gadget to rule them all!
I handled a 9800 in an AT&T store and kind of liked it, but the screen is still too small for my tastes. Heavy messengers and light emailers who don't surf the web much and don't use their phone as their primary GPS will still prefer the awesomeness that is the 9780. BB now offers a form factor for almost everyone. Maybe I could live with a 9780 / PlayBook combo. That BB PB is suweet hardware.