If you ask me, true unification can only be done via Cloud. As long as the game is made with specific hardware in mind (X720), he won't be able to play Halo 5 on his Win8 PC without Microsoft investing in a port. Such unification (consisting of constant porting of titles) would be very impractical. Of course, if Microsoft is willing to make every game effectively multiplatform title (X720/PC) from the start, it could be done in such a way, but in that case you lose the incentive to buy X720.
Personally, what I would like to see in X720 and its rumored new Live version is support for a greater number of countries. For those of us living in territories that are not officially Live supported, we are forced to create fake (usually UK) accounts if we want to access Live.
My first present gen console was X360, but after a year, being frustrated by constant need to use VPN solutions (since Microsoft does IP screening when verifying content restrictions) to download DLCs and certain demos (I think this only happened with 18+ content), I've switched to PS3 which has less strict content policy (verification is done by checking reported account address, plus my country is supported for both Store and PSN), not to mention my decision was helped by Microsoft's threats that they will ban anyone whose location and IP address don't match.
I hope that with X720/rumored New Live, Microsoft greatly expands upon number of supported countries. I just read an article which said that Windows Phone Store is available in 113 countries, let's hope that they will do the same with new Live.