I couldn't find a way to access Rift support while I was playing, nor could I find any way to force it to work. I believe when the game comes out April 4th, people will be working feverishly to find a way for it to work, although I don't expect Bethesda to work on that themselves for a while, if at all. The only method I could think of would be a window duplicator I've come across (but can't think of the name for) that will duplicate the current window. All it does is duplicate the window so you see double, but it's no where close to looking native. And in my opinion, it just looks bad. Plus the email tiling on the screen bending oddly would give me a headache.
I'm doubtful that it will be available at launch, for the simple fact that they will be missing out on a number of core features that are required, ie: Dark Brotherhood.
Perhaps once the Rift is nearing the consumer release date we will have a more definitive answer.
More of a side note since I'm not familiar with the Virieo tools, I wouldn't risk using a 3rd party app to control the display. Most MMORPG's include some form of "anticheating" tools that may pick up on it, and auto-report you for modifying the game (as harmless as it is).
My only issue is the fact that games should be created with VR in mind.. so would the scaling be accurate enough? !@#% I wish I had a devkit >.<
Current WIPs using Unreal Engine 4: Agrona - Tales of an Era : Medieval Fantasy MORPG