OP - I had been thinking the same way recently to be honest with you. $1 billion is a lot of cash, and could fund many many 1st party titles.... but that just doesnt feel like MS's strategy especially based on what they have done previously.
So if we think they are going to fund some 3rd party exclusives, first we need to consider the cost of doing so...personally I think if the game was popular it would cost a significant amount. So how about a different strategy....
Game A - Releases on Xbox, PC, PS3 and *only* nextgen XboxOne. This way MS don't have to upfront as much cash because the current HD consoles will sell just as well (and Next Gen sales will be low initially). I still think it will cost a significant amount but not as much as downright exclusivity.
Of course they could still be doing downright exclusivity on a XboxOne only, but that greatly reduces the amount of sales for the games company and increases the cost of the license.
On another note, I do think EA are mostly in bed with MS, so the rumours about Mirrors Edge being single platform, considering it sold badly when it came out, makes perfect sense (even though i wont be happy about it as a PS3 Mirrors edge owner who would have got the next version).
Capcom are struggling, and Dead rising was exclusive before, so would not surprise me.
As far as Sony are concerned, I wouldn't be surprised if they sold their HQ's to give them more spending power, as they know they need to start the next gen well. Though I am still hopeful that they can get Agent out, as this could be a killer app... but it wouldnt surprise me if its dead.
E3 is going to be quite exciting.. not long to wait now :)












