It's amusing is that some people still prattle on about how other phones are trying to "copy the iPhone UI".
Nobody wants to copy the Home page. It is way too simplistic for serious users.
The fairly static Home page design is one reason why so many people jailbreak. Even users of other phones are no longer installing iPhone lookalike start pages. (What's hot for other phones right now is copying the HTC TouchFlo 3D style. I suspect Apple will eventually copy its cool weather animations. And they should. They're fun.)
Apple had a chance to create something unique, with clever ways of organizing and displaying active personal information, but they opted for a simple 1980's style icon grid... without even 1980's folder capability.
The grid makes sense when you realize they originally didn't want to support third party native apps, or even web apps. The whole idea was to have a simpler phone with just a few nice app choices and no submenus.
But the world and the iPhone have moved on, and Apple will have to come up with at least an optional improvement sooner or later.
Actually Apple was brilliant to go with the very simple and easy to use interface that they did.
There are plenty of more sophisticated user interfaces out there for "power users" but that's not really the target market for Apple with OSX Mobile. If there's anything to be said it's that they are trying to make the iPhone as accessible and simple to use for as many people as possible.
If that means that a few "power users" are crying in their cheerios then that's a price they are apparently willing to pay.