I had some time to play with the N810 while attending 24C3. The interesting part was that I saw quite a lot of people with a N810 in their hands - the ones I talked to had it imported from the U.S.
Since the N810 is mostly like the N800 (software wise) I only checkout the hardware. First impression was very good. The case looks very nice. I think it is a very clean design no bumps or strange edges. (Pictures don't tell you anything when it comes to hardware like this.) For me the most important thing to try was the keyboard since it is the novel part of the N-series. So I was very pleased to find it working just fine - much better then I expected (also I only had a couple of minutes). Sliding the keyboard up and down also seems to work nicely.
All in all it was a nice experience and I'm looking forward to get my own.