The tech specs of the N801 are on the nseries site (www.nseries.com) with additional pictures. The link is posted in another thread. There is also info on the maemo site about the new software (which preserves compatibility! Thanks, Nokia )
I include a picture from the nseries site showing the USB connector and the top buttons and two pictures showing the back and the keyboard sliding (those were taken from the flash animation and are not very sharp, sorry).
-size is the same than the 770 (smaller and thinner than the N800)
-same processor than the N800, but 400 Mhz instead of 330 MHz
-same system ram and flash than the N800, but 2 GB internal storage (presumably for the maps...)
-ONE slot, miniSD
-ambient light sensor (?)
-support for 3GP and H.264 (video podcasts in the iPod format, maybe?) and flash 9 video (youtube?)
-the hardware keyboard exists in different languages
-the USB connector is indeed different (see picture)
This is going to be a very nice machine. This is also, presumably, going to be a relatively expensive machine (if only to cover the price of the maps), and will require N800 owners to buy new SD cards and new batteries (if needed).