I don't know, I kind of like the 3-row keyboard. It's already hard enough to reach the top of the screen while typing. I have a better solution: the N900 has enough space on the sides of the keyboard to add an extra column. Then make space one button wide, and you have four new buttons. Would much prefer that layout, personally.

Edit: other things to keep:

-Would rather have better keyboard and lens than slimness. (Although a few mm less would be nice, if you can pull all three off)

-Display tech doesn't matter to me as long as the device still comes with a built in stylus. It's essential for running desktop apps, and I would be very unhappy to see it go just for some stupid coolness factor. I also don't want to carry a separate stylus with me, even if it ships with the device, so keep the hole.