The idea also is to write iPhone applications in C++ instead of ObjectiveC/Cocoa which as a steep learning curve (not objC per se but the way cocoa works takes time to learn...)
Not sure what your background is but for most people learning ObjectiveC and Cocoa is much longer than just learning a new toolkit. I have no problem programming in ObjectiveC with Cocoa but may people really do.
I've shipped in Motif, GTK, and Win32, and I know ObjC/Cocoa; of these 4, Cocoa was by far the easiest. Can you point me at some critiques of Cocoa vs., say, QT?
Again, I get that it's cross-platform. But that's not a huge win for the iPhone, which is so idiosyncratic that any good app is going to be one big special case for that platform.