You can use it. For exam there IS a mirror application.

But words "fails in the software departure" can be applied to closed OS - you have no chance w/out manufacturer. If we speak about Linux it is not closed at least it is definitely open on valuable levels. So, it can be said "there is no enough Linux applications for you on N900" but not "N900 fails".

As for the applications selection... you know, it is very individual. As for me I don't care about games and similar stuff, for me N900 is a communication device to communicate with people and computers. At this level it plays very well, not ideal but very well - SSH, VPN, FTP etc + GTALK, Skype, SIP, chat, messaging etc.

The only thing that I miss now - video calls from skype.