Microsoft has gone all in when it comes to backwards compatibility on the Xbox One and this will continue into the next generation and Project xCloud.
According to the official Microsoft Xbox Wire news site:
“There are currently more than 1,900 games in development for Xbox One, all of which could run on Project xCloud. Developers creating those games continue working normally – building with the tools they have – while we do the work to make their games accessible to the broadest set of players possible.”
All of this, of course will run off of Azure tech, which Sony will apparently be using for their streaming services as well according to the recently announced strategic partnership with Microsoft.
If you as me, I’m not sold on this whole streaming feature yet. I’m a cynical old school gamer who fears change.
However, if you give me the best of both worlds, letting me play locally but give me the option to stream when the conditions are optimal, then you have my attention.
[Source: Xbox Wire]
Spieler Dad 
I’m firmly in the I’ll-Believe-It-When-I-See-It camp when it comes to game streaming. Being able to pick up a game anywhere and play in a high-fidelity, lag-free environment sounds amazing, but I’m skeptical as to whether we are there yet.