From a hardware perspective, its like two different companies made them. The feel of the slider and even the keyboard are better. The n810 has better travel with the keys but because its a bigger device, there'smmore finger stretching. The browser is much improved and if not for a few silly decsions with ui, it would be a lot better. Lastly, battery life is pretty sick on the n97. This thing lasts a long time.

I'll have to hold out a bit longer for more indepth compairsons since i've got other phones i'm compairing this to and i don't yet have an n97 of my own. But this is indeed encouraging both for future tablets and nokia devices in general.