As you can see Windows Mobile 6.5 has some asthetic differences over the current 6.1 version. Besides the start menu now spreading out into a honeycomb for "finger friendly" selections, probably the most exciting features for windows mobile users are the My Phone service and Windows Marketplace for Mobile.
The My Phone service will be FREE and in some ways will mirror Apple's Mobile Me. Many details still to come on this one.
There is no doubt that one of the coolest things about the iPhone is the seemingly endless selection of applications and the ease of adding those applications to the phone. Microsoft woke up from their nap and will attempt to close the gap between the iPhone and Windows Mobile phones, by allowing users to search, browse and purchase mobile applications through Windows Marketplace for Mobile.
Release date on WM 6.5 is sometime later this year.