The flood of realtime GPU path tracers and renderers keeps continuing and Octane Render is the latest newcomer. It's made by Terrence Vergauwen, a Belgian and compatriot of mine :-), who was the former lead of LuxRender. It's incredibly fast (currently CUDA only): www.refractivesoftware.com
Be sure to check out the video. It might not be as impressive as the iray video, but that was runnning on 15 Tesla GPU's, while the Octane video was recorded with 1 GTX 260!
The ever growing list of GPU renderers:
1 V-Ray RT GPU
2 iray (mental images)
3 LuxRender OpenCL (smallLuxGPU, David Bucciarelli)
4 Octane Render (Refractive Software)
5 BrazilRT (Caustic Graphics)
6 FryRender, Maxwell ????