N900 going to very hard to beat when you look at the pure versitality of it so no idea when or even if anything will match it even in the distant future.

One thing the N900 has taught everyone is how much it can actually be hacked and that is a first and probably a last for Nokia and i very much doubt any other manufacturer will even have the guts to bring out such a playable device for a long time !.

Anything in the future would have to be 100% open source because people have been burnt by the lack of support on the N900 and will watch very carefully from here on before getting involved in such a device again.