I don't think MS will be last by more than a few weeks. The next Playstation will release at the end of 2013 just like the next Xbox. I also think that it depends on many things. If both consoles offer all the same again then the cheapest one will gain more market share. Then the one with the most interresting exclusives coupled with 3rd party games will secure the first/second position.
I do believe though that the 3 consoles will share similarities like WiiUPad/Vita/Smartglass so most games offer the same experiences. But the core consoles will be more unique. MS's next console will come packed with Kinect 2 allowing devs to take full advantage of the Kinect and thus offering gameplay elements not available on other consoles. The same could be said about Move 2 but I believe it'll be optional again and will share games with WiiU (some devs might even make games only for PS4/WiiU and make a different version for Xbox8 because of Kinect being too different.
People think MS will not create more exclusives next gen but they can't be more wrong. They'll have to. Mainly because the next version of Kinect will help them secure domination in America. Building games not possible on the competition will be key at the start of next gen.
It will all depends on what the next consoles have to offer and at what price. Noone will repeat Sony's ridiculous PS3 launch price and I don't think WiiU will be that popular. Sony has to come up with more than just exclusives if they want to compete agains't Microsoft. Kinect, Smartglass and all Live has to offer just stole America's heart. And seriously, even if they are mostly popular in America, They are about even in Europe and Sony tremple MS in Japan but it's Japan, not the powerhouse gaming wise it once was...
