Nokia needs to rework their ideas about phone support.

They're still stuck with the idea that they make a custom build of their OS for a particular phone model and then move it into "support only" where they make minor tweaks or bug fixes.

Apple changed all that completely. People now expect continual updates for their phone with new features and new applications. If Maemo 6 comes with features the N900 cannot support then obviously it can't have those features but there's no reason why it shouldn't get everything else.