I use Skype over Sprint's 3G on a Touch Pro and it works perfectly. The audio quality is comparable to normal phone calls. There's no reason why it wouldn't work.

The operating system required to run the development tools is obvious, and everyone who would buy a smartphone has or has access to a copy of Windows. As for Visual Studio, the trial works perfectly with full functionality and no nagging - I miss Ecipse and the CDT severely, but it's certainly workable, and it's free. If you're desperate, it's certainly easier to afford this setup than the initial outlay for iPhone development, for example, though I would rather work on Android programs.

Perhaps not, but when talking about phones, it is the most open platform short of Android. You can install anything without any restriction and develop applications for it with no initial cost. That's part of the reason I didn't buy an iPhone and went with a Touch Pro instead; some things are very frustrating, but nothing would be more frustrating than not being able to do what I want with my own phone, and Windows Mobile sadly comes closest to that at the moment.

First of all, you don't "patent" software - you patent portions of software. Patenting entire pieces of software would make no sense, as it would do nearly the same darned thing as copyrighting it. Second, what defines complex? All software ideas are complex. Is a BSP tree sufficiently complex? I imagine so, and a patent on that would have decimated the game industry early on.