The title of this thread hits upon why businesses don't usually care about giving you software freedom on your hardware, especially with phones.

But on the other hand, Nokia would naturally bundle other stuff on top of the hypothetical-N950 (was there ever an official end to the N9 btw? Or did the rumors of that just fade and rumors of N950 came instead?), which could potentially be worth the upgrade. (But at the same time, one of my computers still runs Windows XP - there's nothing wrong with skipping upgrade iterations - that doesn't mean that there's no point to buy the hypothetical-N950 if you never had an N900 but were sitting on an even older phone until then. One can hope that as phones get better people will realize they don't need to upgrade every generation. Everything you use still runs fine a couple of years down the line, even if there's stuff that's technically better.

Also, keep in mind, as far as we know the N900 successor is NOT MeeGo, but is Maemo 6 renamed to MeeGo for branding purposes. It wouldn't be running true MeeGo. And even if it was there'd be a good chance that the official Nokia implementation on better hardware would run smoother/better than on the N900.