Bad APIs, outdated/incompatible libraries, lack of communication as far as upcoming features. Limited/zero documentation of core features. Limited/zero API access to core features. Closed-source core functionality set (browser, drivers.) No browser plugin SDK. Dated browser. Dated flash. No support for the APIs/software of any other mobile platform (QT/Embedded, J2ME, Symbian, Windows Mobile, Palm). Compatibility was broken with the N770 for poor reasons.

The ITOS tablets are closed-standard closed-source projects very similar to your average cellphone. That's fine, assuming the feature set that gets shipped is rock-solid. It's not.

ITOS users have little clout to demand compatibility --- very few people treat it as a serious target. ITOS developers have little power to provide compatibility --- much of the OS and feature set is proprietary.

I'm not expecting anything earthshaking until Ubuntu Mobile (or some other major distribution) supports the N800. Nokia did a fine job with the hardware and some points, but is doing a terrible job with managing the platform.

EDIT: One more thing. Developers are motivated and demotivated by a certain set of criteria. Owning the device (and the discount!) makes me inclined to do a certain level of work to adapt it to me. There's a limit to the amount of uncompensated work I'll do to improve a device when substitute devices already provide the feature set. The developer community is simply not responsible for fixing core issues.