After playing with the new iPad SDK I must say: I want Cocoa Touch for the Mac. Especially the UISplitViewController stuff.
I'm using for one of my recent Mac projects a split view with a custom split view controller and tinkering with the boiler plate code is just a mess. And when I look at the new iPad SDK I must admit that I love UIViewController - it's easy and it's effective. We need something like that for desktop Cocoa. ASAP!
Heck - we need a lot from Cocoa Touch on the desktop. The NSViewController stuff on the desktop is just a mess and does not add much value at all. You have to do all the ugly boiler plate yourself. In contrast you have on the iPhone the fantastic UIViewController components which make coding for the iPhone just fun. And the new UISplitViewController is just the next level.
So my plea to the mighty cocoa gods: Please improve desktop cocoa to the level of the iPhone SDK!