First Thought: Something new, original and interesing.
Second Thought: Balance between complexity and accessibility. Deus Ex, System Shock, Thief and Hitman did it right. Nowadays it seems accesibility means simplification. Which it doesnt.
Third Thought: We have it. It's called a controller and a video game system. I mean, the graphics are going up, technology is going up, giving us more possibilities, with say, physics and depth, but aside that, I am very happy with a controller and a console/PC and keyboard. So in my mind, we hit perfection in the late 70's and just have been refining that perfection. Motion controls, voice reckognition, all that stuff, are in my opinion, novelties, but overall useless and a step, not necessarily backwards, but just sideways. There is no point to them, even though consoles like the Wii might be super fun.
And Lastly: Respectful community. Why are 90% of gamers entitled assholes? Before people start acting like normal fucking human beings, we will never be taken seriosly.