I think MS did an amazing job this gen. When I bought my Xbox 360 I did not expect to get anything of the stuff I have right now. Heck I did not even expect to get Resident Evil, GTA, Final Fantasy, Tekken, DMC, MGS etc. let alone Movies, TV shows and all this kind of stuff.
MS is the only one out of the three who made it perfectly clear that Xbox Live is the heart of the Xbox 360. They have more than 35 million XBL users and all of them are connected with each other. So there is a big chance that a big percentage of them will be picking up the next console as soon as one of their friends have it. I know this goes for every console out there, but with XBL you can probably chat with someone playing this over-the-top-freaking-awesome-game you can't play on the Xbox 360. Posting achievements on facebook, you can't have etc etc.
So I think their biggest advantage for next gen is XBL and NA is the place where XBL has most of the features.
This reminds me: How freaking hard can it be to upgrade your XBL friendslist. Do yourself a favour and just do it, MS!
Windows 8, MSN /Windows Live Messenger, Facebook, Twitter, Skype, Windows phone 7, Zune, Xbox Live all need to be connected beyond everything we have seen so far. All you need to do then is to have a $400 release, good line-up of games right from the release and a good marketing campaign.
On the other hand, you can shoot yourself in the foot big time with every new hardware release.
Imagine not having GamePass on your console...
