It's been a long summer, but not long enough because SM Media Arcade has missed its targeted release date and pushed it back to the end of October.
While this first beta will be a little rough around the edges, it will be full-featured in and of itself.
The user interface of the beta will give you complete control over your 3D desktops. The UI is bland, but very functional.
Unfortunately, the beta will not be able to load images via http addresses. But it will come with marquee and screenshot images for over 100 popular Steam games and general images for other types of media's avatars.
Don't forget that manually adding a marquee or screenshot for a game or media item can be as easy as dropping the image in a specific folder, or alternatively referencing it from where ever it's at.
This ModDB profile is brand new, so keep an eye on it for updates and new videos and demonstrations as they are made available.