I don't actually have one of these but I played with one for a good half hour in an AT&T store today... The keyboard may seem small
but I had absolutely no problem typing on it in both portrait and landscape...and this is coming from an iPhone user (switching to android soon) so I've been using a touch-keyboard for two years...
Plus, with swype coming out (yes there's the whole side-load thing but there's a work-around for that) a lot of people seem to love swype. So that should work fine.
Overall though it didn't seem too cramped, and I've got normal sized guy hands.