I have a 770 and I've also been waiting for the next tablet. I don't think the N810 would do it for me, since I already have a BT GPS, it runs ok on all sites to which I need immediate and mobile access to (email, Google), and Canola for media playing does it for me. The hardware keyboard is a nice addition, but the lack of screen cover is a major turnoff - I dropped my 770 on pavement quite a few times, and aside from scratched and damaged cover (which it only makes it look cooler, IMHO), the tablet is quite healthy, thanks to the cover.
I only hope we're gonna see a IT2008 release for 770 (even a stable hacker version)