It is not very hard for Nokia to capture market back just on n900 if they pay a little attention to it and introduce few apps on it for free :
- Ovi maps with turn by turn voice instructions
- voice dialing
- Video calls
- skype functionality similar to their Symbian phones
- MMS (thanks to the community developer we already have it)
- ear phone that has controls integrated to phone like n97/5800
- flash 10 will be awsome.
- some business apps or integration to rates feed
- fix up email
and few more.

Some of the above functionality have been developed but not by Nokia.