@eastmen I think the incentive would be forwards/backwards compatibility. You buy games knowing they'll run on the next console, when you choose to get it. You buy the console knowing there's a huge library of older titles available, beyond the new games available at launch.
But outside of a few hardcore gamers, how many truly care about BC? PS3 bombed at launch even though it had PS2 BC. Wuu bombed even though it has Wii BC. X360 sold loads more than Xbox even though it didn't had BC.
I doubt the average consumer is going to buy a bigger and better box just to play old games. Besides, its not like buying a new console means you cannot use the old one anymore. Anybody really interested in playing his old games will just keep his old console. That 100 bucks you might earn selling it aren't really going to make a difference. Besides, those buying a used old console probably want one with a few good games.
BC is good for devs and pubs, but then we aren't talking about disk based BC but software BC so they can just put their old software up on the store so people can buy the old software for their new console at a reduced price and cash in on the same game twice that way.
I don't see the point in hardware upgrades for a console.
The whole concept of a console is that you got a relatively cheap box that you know will run all software released for it for the next ~5 years and is plug and play. No worries about performance of having the right expansion.
Same goes for the devs that don't have to worry about whatever many varieties there might be. Are devs going to be required to update old games to work with new expansions? Or what is certain combinations cause issues? Will devs have to create updates?
How are consumers going to take this? If they see a game advertised with gfx made for the gpu expansion they don't have will there be backlash when they get home and it looks and runs totally different on their system?
Consoles with hardware expansions or upgrades to me sounds like a gaming device we've had for decades. It's called the PC.