I think that Microsoft needs to make Windows Mobile Pro more "touch-friendly". Some items on the screen are very small and hard to tap with your finger making you use a stylus. Windows Mobile Standard is great. Pro just needs to be more touch friendly.
The hardest thing I have trouble tapping with my finger is the red-x to "fully close out an app"[1]. I have attached an image if you are unsure of what I am talking about.
My biggest disappointment with Windows Mobile is that we must wait for the carrier to release and update. With other phones such as the iPhone, the minute the update is done, it's released. No waiting on Voda, Verizon, ATT, whoever to release the firmware update.
With the .NET CF and Java and Flash 7.0 being able to run on Windows Mobile, I don't believe that it is going anywhere soon. People will continue to make great applications to run on this great platform.
[1]Please fix this Microsoft. When I click the X in an application, I want it to be closed! Not minimise to the task manager.
Link to image - http://img379.imageshack.us/img379/7741/picture001pj1.jpg
(For some reason the Add Image in the editor isn't working)