Many people have already heard of Bluestacks. An Android emulator which helps drive another 750,000 applications for the Surface Pro. The latest version however has been optimised specifically for Windows 8 and the Surface Pro.
The software has a Metro style, full screen interface for applications and a Charms menu that activates with an edge swipe. Android applications should now effectively run like a native Windows 8 version.
The software should help expand the Windows library significantly.
I haven't had the chance to extensively test the software yet, but I did try a few programs on Windows 8 last night and they seemed to run quite well. It is worth pointing out however that many of the programs which will be running under emulation are native phone applications which will be scaled to fit the screen, suffering from aliasing.
Find out more over here.
Kitguru says: Sadly Bluestacks won't run on a Windows RT tablet due to the architectural differences.