I think, weather/time of day/Birds.... would be cool, also Some kind of commentry e.g (Player 1 has entered the Pits...) i know this is an addon i could download, but think it would be good in the official game.
Only Scawen knows, though I suppose not even he is sure what exactly he wants for S3. However, the general direction for that seems to be weather and graphics.
For patch Y, he said his main focus are AI and physics.