I was looking at the new qt interface on youtube, it is definitely smooth, I can see GTK+ being smooth if some one invested time in making an optimized backend.

Anyway, I wouldn't ditch my N810 to get it but I am so tempted to get it as a cell phone, I just wished it had a 2MP camera (and maybe a bigger display), I use the camera on my cell phone so much for lots of important things, like taking pictures of white boards with ideas or schedules from meetings, or in other situations. I feel a camera is more essential on a phone then a GPS or accelerometers (though those are nice things to have).