Not a whole lot was changed in the Windows Mobile 6.1 to 6.5 upgrade. That’s why it was only a 0.5 upgrade. Microsoft has some work to do, but I have a strong feeling that they know this.
The overall user interface is slightly different from 6.1. It almost looks like they smashed the Zune UI and Windows Mobile 6.1 UI together.
SMS Messaging and e-mail were left pretty much untouched.
A new lock screen allows you to view missed calls and text messages with a simple swipe of your locked device. A small improvement over 6.1.
Lastly, the most obvious change is the “honeycomb” redesign of the start menu. In order to make their OS more touch friendly, they created a honeycomb style display. The idea behind this is to make it more touch friendly. Users won’t be accidentally opening programs as much since the icons are farther away from each other.