1) thickness: keep in mind how much this device offers. for everything it brings i think the size is very good. surely devices like the iphone are smaller but they have less features.

2) touch screen: you may be right here. But even though you notice that in the "interaction documentary" (http://www.youtube.com/watch?v=RP5R-5NX1BE) the guy presses relatively hard on the screen, i think it looks like resistive TC's have been improving and the needed pressure looks quite reasonable (non-problematic) to me.

3) browser: sure, the default browser may not be perfect. That's why the community is coming with alternatives such as tear.

4) track record: others have already said exactly the same as what I would say.

5) apps: that may be true. but i don't see much problems here. the n900 looks quite "usable by default". the most important thing here is the community, which may not be as big as e.g. the appstore community, but OTOH it's simple to port applications to maemo (it's a Linux with a "normal" userland, unlike android)

6) landscape: what others said.

conclusion: it's still early to tell. surely there are optimistic and pessimistic opinions. I seem to belong in the former group, just remember one thing: what nokia brings us is only 1 half of the story, the other half is the community