Never mind Portal 2. I want Valve to bless us with their brand of perfection in a game based in Space. Like Freespace meets Tie Fighter meets Half Life 2 meets this game: http://www.infinity-universe.com/Infinity/index.php?option=com_content&task=view&id=12&Itemid=33

Valve is very good at controlled-environment games. And they're fun. But I'd like to see them create an open world to explore. I have the feeling that if Valve created an MMO they would make billions.