It would be super neat if MMF2 could get this feature put in, since it could probably be done (in HWA at least) by just copy/pasting the same code used to rotate object textures and giving it an option through the storyboard controls menu / layer object. Especially if Francoise happens to be reading this thread <.<
I figure just rotating the texture and letting the developers worry about cropping the screen to cover up the edges would be plenty great, considering how often I get the request, and how you can use the existing subapps or virtual frames to manipulate it to crop the edges. As a reminder- the whole idea is that the vertex shaders would run substantially faster on a 512x512 texture than a pixel shader would. I think. Maybe. Maybe not, but it would make it a whole lot easier to help other people do at any rate.
Oh and thanks again for GDC!