MS's next XBOX already looks to have several disadvantages in terms of cost

[Final-Fan]

HappySqurriel said:
One of the nicer things about consoles being able to update their OS/Firmware is that (hypothetically speaking) any of the console manufacturers could make it so that a game could run on their current generation system with low-detail graphics while the next generation system could have a high-detail version of the graphics. This is a lot like how PC games work, and should allow for some improvement from buying the next generation system while still preserving support for the current generation system.

Is this truly possible/practical?  I don't really know anything about it, but I had had the impression that console OSes were built much more closely around the hardware, so it couldn't really be able to "bridge the gap". 

I mean, I'm sure you wouldn't have brought this up if you didn't have reason to believe it was possible, but it sounds MUCH too good to be true. 

And from a more cynical standpoint, the transition from old to new systems is already so messy that I'm not sure anyone would dare.  But that's a-whole-nother discussion.