Perfect All Around Bullet Proof CSS Framework: From Mobile To Desktop

So I am very impressed and enlightened by Yiibu's presentation about CSS on mobile devices: slideshare.net/bryanrieger/…

Is any of you using or in the process of creating a CSS Framework that covers those principles including browser hacks and graceful degradation down to IE6 which is lightweight?

I would like to look into creating this sort of thing. There are many CSS Frameworks out there but they each only cover a certain spectrum. How about putting the best ones together intelligently and create the one that does it all?

Or has that already been done?