I don't think anyone is suggesting that this device is for laying flat on the table and typing. I think it's intended to be at thumb keyboard used in the same fashion as a T-Mobile Sidekick or MDA or Wing. You hold and type on it in much the same manner as you would the N800's full screen keyboard, except that the screen is above your thumbs instead of under them.

I think a lot about ergonomics, and even though the N810 is warming up for me the more I think about it (I don't have a huge investment in SD cards, so why not buy a MicroSD->MiniSD adaptor and standardize on MicroSD cards now? things like that), there are still some real design concerns I have about the N810.

The Dpad placement on the N800 is ergonomically ideal. The base of both thumbs hold the N800 against the ring and pinky fingers. The tip of the left thumb then rests easily on the Dpad. It doesn't have to extend/stretch down to use the Dpad (as it will on the N810), and it doesn't have to flex excessively (as it does when using the escape/menu/home button on the N800).

The best way I can see to address the ergonomics of the thumb placement, in a device as small as the N800 and N810, is to:

1) put the d-pad in the upper left, as on the N800
2) put the escape/menu/home buttons in the upper right, where the Nokia logo is on the N800 and N810 (move the Nokia logo to the bottom center, at the lower edge of the screen)
3) do not have the side-bars slide with the screen. Look at the new Motorola Sidekick Slide for what I mean here (or the Sony Viao UX, or the chinese prototype red linux umpc). Only the screen slides up, to reveal the keyboard, while the places you grip the device remain stationary.
4) slightly divide the keyboard, and separate the two halves, the exact placement being made for ideal thumb reach. Make sure neither thumb has to excessively stretch to each the center of the keyboard (left thumb for the G key, right thumb for the H key), but also so that neither has to excessively flex to reach the edges of the keyboard (left thumb A, right thumb semi-colon).
5) I'm not sure if the right/best place to put the chat cam is between the two keyboard halves, or at the top center edge of the sliding screen section (sort of where the Macs put their chat cams). The light sensor probably should go at the top center, whether the cam is there or not.

I have NO doubt that if Nokia does an actual formal usability study comparing this layout to the N810, that his layout will be far better. It might mean going back to the slightly longer form factor of the N800, but I think the ergonomic win would certainly justify it.

Add in a tilt for the screen (that can be tilted even if you don't slide the screen, then you don't need an integrated stand), and you've got a very compelling design.

Yeah, I'd prefer if the full screen keyboard still allowed you to see part of the application, the way the stylus keyboard does. Sure, it'd be a tiny part of the screen, but it would feel more like live input than what you do now.

If they're going to make a larger device, then I don't want to see a micro-laptop. As much as I have some like for the idea of a "laptop in my pocket", even if it's my jacket cargo pocket, having the keyboard at the lower edge of your device isn't really a good idea.

If they go to a bit larger form factor (esp. if they do it as a second product line; lets call it a "Nokia UMPC" in contrast to the "Nokia Internet Tablet"), then I want to see a form factor like the PepperPad and Samsung Q1/Q2. This design really embraces the ideal thumb positions for the integrated keyboards. The left half of the qwerty keyboard is in the upper left part of the device, the right half of the qwerty keyboard is in the upper right part of the device, with the touch screen being between them. The Dpad is slightly below the one of the two keyboard halves and the other special buttons are below the other keyboard half.

If Nokia makes an UMPC, that's what I'd like to see. Unfortunately, I don't think you can comfortably make a tablet with that arrangement. The WiBrain, I think, is trying to do it ... and it's REALLY long (9 inches I think?). I just don't think it'd work for the intended size class of the 770/N800/N810 devices.

That said, I WOULD like to see Nokia go into that product space. But only after the "5th step" in the 770/N800/N810 is finished, and only with caution (don't bet the farm/company stability on it). But having a "nokia umpc" that 's fully compatible with the "nokia internet tablets", but with more expandability (video out, more USB options, etc.), larger screen, more battery life, and more storage/memory would be a nice product to see. As with the other UMPCs, cell radio could be omitted: you could use the Internet Tablet as your tether, if the 5th step in that series includes a cell radio. That way the two products work together.