Objective C's collection syntax is terrible and is easily the worst thing in the language. Apple fixed it with collection literals in OS X 10.8 though and those enhancements are almost certainly coming to iOS soon.
Is it true that those are only available in 10.8? It thought they just compiled to +[NSArray arrayWithObjects:count] calls, which would work anywhere.
As far as I understand they required patches to LLVM so it may be that the resulting code would also work on older releases and don't need runtime support. But the version of Xcode that supports them is only available for Mac devs, as far as I can tell.