Im sure by now you guys already know about shadowplay and what it can do and the most exciting feature has to be the ability to hit a key when something epic happens and your last 5 minutes or whatever are recorded even if you where not actually manually recording at the time.
Fraps has a similar feature called Loop buffer where you hold down your record button at the start of playing and then hit the record button again shortly after that "epic" moment and it will continue recording with the gameplay from the last few minutes added to it.
As i understand it fraps is basically capturing whats going on and then throwing it away when the buffers timelimit is reached I guess thats what shadowplay is doing too the difference being shadowplay doesnt give frame loss or at least very little. Fraps hurts frames way too much.
Action is great at not really hurting frames so if you could add something like this it would be amazing. Not really a fan of fraps way of doing things because you have to tell it to start in the first place so perhaps if possible have it auto capture so long as action is open or maybe have it start when a game is open. I know action does more than gaming but im not sure its needed outside of gaming but who knows.