I believe the roadblock here is the lack of support for automatic garbage collection for applications developed using the iPhone SDK in the mobile OS.

I'm a Ruby developer, not iPhone/Cocoa so this could be way off base, but I believe this is what it came down to in a previous discussion.

MacRuby relies on the Objective-C garbage collector, which is disabled on the iPhone.

So would it be possible to plug in another garbage collection scheme...just for iPhone apps?