SQLServerPedia

They drew the line in the sand at the OS.

First and foremost, 32-bit is done. History. Archives. Windows Server 2008 R2 is the first Windows OS platform to go 64-bit only, and frankly it was high time. Customers have been unable to purchase a 32-bit server CPU for over two years now, and the advancements in CPU architectures really dictated that we squeeze as much performance out of customers’ hardware purchases as possible. The move to 64-bit is a first step.

Read the full post here.

I assume they *could* still support SQL11 running in wow64. We will see. I gave my opinion, as did others, in this post a while back.