What is the best way to start developing Windows Mobile Professional applications in Python? Is there a reasonable SDK including an emulator? Is it even possible without doing excessive amount of underlaying Windows API calls for UI for instance?
(I used to write customer apps for Windows Mobile.)
Forget about python. Even if it's technically possible:

your app will be big (you'll have to bundle the whole python runtime with your app)
your app will use lots of memory (python is a memory hog, relative to C/C++)
your app will be slow
you wont find any documentation or discussion groups to help you when you (inevitably) encounter problems

Go with C/C++ (or C#). Visual Studio 2005/2008 have decent tools for those (SDK for winmo built-in, debugging on the emulator or device connected through USB), the best documentation is for those technologies plus there are active forums/discussion groups/mailing lists where you can ask for help.
Windows Mobile development in Python