I haven't managed to get anywhere with 2.9.0 on my n810 running the latest diablo updates. It will install, but it breaks microb (when you open the browser a small 'Updating' popup appears and never goes away; microb will not browse to any pages.) Uninstalling gears did not correct the problem, and I was in a hurry to get the tablet back up so I just reflashed and restored a backup.
Gears would be incredibly useful to have on the NITs, but it seems that the guy responsible for the 0.2.9 version doesn't have time to maintain it right now. I grabbed an SVN snapshot and installed scratchbox, but I'm pretty certain I'm not sufficiently skilled to get a port worked up. I'll poke at it some and if I make any progress I'll let you know, but I'm quite doubtful.