People have tried that, it didn't work apart from getting Nokia to provide OS 2007 on 770 in an unsupported and semi-working form.

I think Nokia have learned from the 770 to N800 transition and will hopefully not make this mistake again when releasing any successor for the N800. If they make the same mistake again, then they deserve all the aggro they will undoubtedly receive. But that scenario is way into the future, and worrying too much about it now is not likely to be productive as there's little we can do about it - it's a fundamental Nokia business and technical issue which we will not be privy too in any shape or form.