As a person who has never owned an Xbox but isn't a biased fanboy and feels a desire to own one of their consoles to catch up on the exclusives this is a really big discouragement from thinking about Xbone. I know that what I really want to play on an X360 are Halos, GeoW (loved the 1st part on my PC), Alan Wake and the 2-3 exclusive jRPGs, maybe also Fable. After they decided to port Halos to Xbone, I've decided I'm waiting for news about the 4 GeoWs being ported over and I can forget about being a late adopter of X360 and go with Xbone instead (it's not like X360 is much cheaper at this point anyway).
But...
MS porting every single exclusive to the PC is a twist again. So you're saying I can play all these games I'm interested in without paying for the console and not bothering to paying for Live? That is actually awesome and is a big reason for someone who sees the MS console as the 3rd option to skip it and go with PC versions instead.
Just my point of view 
BTW. If they care about sales and getting people aware about the franchise, they should port it to PS4 
Wii U is a GCN 2 - I called it months before the release!
My Vita to-buy list: The Walking Dead, Persona 4 Golden, Need for Speed: Most Wanted, TearAway, Ys: Memories of Celceta, Muramasa: The Demon Blade, History: Legends of War, FIFA 13, Final Fantasy HD X, X-2, Worms Revolution Extreme, The Amazing Spiderman, Batman: Arkham Origins Blackgate - too many no-gaemz :/
My consoles: PS2 Slim, PS3 Slim 320 GB, PSV 32 GB, Wii, DSi.
