We got to play on a GeForce GTX 260 + ATI Radeon HD 4890 running in multi-GPU mode
 

Of course with two different GPU vendors, we need Windows 7 to allow both drivers to work at the same time. Lucid's software runs in the background and lets you enable/disable multi-GPU mode. If for any reason Lucid can't run a game in multi-GPU mode, it will always fall back to working on a single GPU without any interaction from the end user. Lucid claims to be able to accelerate all DX9 and DX10 games, although things like AA become easier in DX10 since all hardware should resolve the same way. There are a lot of questions about performance and compatibility, but honestly we can't say much on that until we get the hardware ourselves. We were given some time to play with the system and can say that it at least works. Lucid only had two games installed on the cross-vendor GPU setup: Bioshock and FEAR 2. There are apparently more demos at the show floor, we'll try and bring more impressions from IDF later this week.

http://www.anandtech.com/video/showdoc.aspx?i=3646

Very cool, promising technology... hope it lives up to the promise. :)