My hope is that nokia will see how popular the N900 is becoming, and realize how important support for this device will be to the future of maemo.
The next device based on the speculation I've read, will be more of a tablet than a phone. Much bigger in size than the N900. The N900 might still appeal to a very large crowd more than step 5, because of its size. other maemo devices are not even on the horizon yet.
In other words step 5 and the N900 might not actually have to compete with each other.
A steady growth in popularity of the N900 might force Nokia to invest more into perfecting the device, and maybe even porting maemo 6 to it.

Really I'm just hoping... Who knows what'll happen.
In the meanwhile I'm certainly enjoying my N900 now!