It was also mentioned in the comments for the latest blog post that there is an OpenGL build for Windows, as well, but Swen wasn't familiar with the details and thought there were some problems with it. Assuming those issues can be resolved, that may potentially remove the requirement for a DX 11 card in Windows.

That was after it was revealed there would be an announcement very soon, which would include information about the Linux version.
There is no 'may'; the EE has been officially announced for Linux and SteamOS.