His competitive service seems more comprehensive than the one provided by Autodesk. For instance, it has an EasyView window that shows you the progress of the rendering as it is performed by nVidia GPUs on Amazon's computer farm. (Video.)
The video shows a model taking six hours to render in Revit, but just a few seconds on Amazon. (Using a RevUp browser window, the model viewpoint is changed, and the scene is re-rendered in a few more seconds -- nearly interactively.) As I asked in upFront.eZine, is Revit just really s-l-o-w at rendering?
RevUp supports more CAD programs than Autodesk's own stable, including ones crucial to designers, like SketchUp and Rhino. With third parties providing the service makes one wonder, Does Autodesk need to be in the cloud rendering business?