Just nitpicking, but micro-usb and mini-usb are both super tiny and it seems hard for something to be "between" those two sizes. Aren't they within millimeters of the same size?
The main reason that I see to making a smaller dock connector is for a larger speaker and microphone grill, so that is welcome. The iPhone 4S speaker volume is already good, but not great. Especially for conference calls and speakerphone situations, which are very common in Enterprise world, better and louder audio is needed.
(Don't even start with the $30 adapter BS, ya they enjoy it, but it's not the reason for doing it.