Basically the NVIDIA software suite that will gather your hardware like CPU, Memory, Graphics card etc. Your data will be send towards NVIDIA's servers and based on your PC hardware an evaluation (for supported games) will be made. The software will then configure the game for you (this is in-game, not driver level).
The idea is a little controversial we agree, but for those with entry-level and mainstream PCs it could help them setup and play the game more easily without going through all kinds of in-game settings themselves.
So NVIDIA today launches an open beta for 10.000 users in an attempt to gain user feedback on this project. Now this is not a 100% set number from what we heard, so we'll be hosting this beta ourselves later on. NVIDIA asked us if we could generate some feedback.
Give it a try if you'd like to of course. And please leave your feedback in this thread, we'd appreciate that, thanks.
The initial games supported in this first Beta are.
So for those interested in testing and participating in the GeForce Experience please download your copy.