I'm not proposing a virtual machine or a new language; C++ and the Source engine seems to be working fine for LFD2 and Portal 2 and other AAA titles.
I'm proposing liberal licensing for the engine and adding a simplified API for 2D games. You are correct that you can't optimize for every platform at once, but that's what #ifdef is for. Extra work is still required on each platform... if you need the extra performance.
Mostly I can't imagine Valve putting the effort into Linux if they don't have a plan for getting more games onto Linux. I was just trying to guess at that plan.
I'm proposing liberal licensing for the engine and adding a simplified API for 2D games. You are correct that you can't optimize for every platform at once, but that's what #ifdef is for. Extra work is still required on each platform... if you need the extra performance.
Mostly I can't imagine Valve putting the effort into Linux if they don't have a plan for getting more games onto Linux. I was just trying to guess at that plan.