None of the ARMs I carry with me run WinMo or had binaries compiled with VC++. The odds of WinMo devices outnumbering competing devices are very slim.

But you surprised me now: wasn't WP7 managed code-only? Has MS decided to allow native app code?

Yes, the number of non MS-ARM devices is probably several of orders of magnitude more popular. But you'd be surprised at how many embedded devices run Windows CE.

Regarding WP7, 3rd party apps are managed. But the core OS is native and 1st party apps can be native. For example, IE and the mail app are both native C++ apps.

Honestly, I think allowing 3rd party native apps would be a mistake in general. Although I'd create a partners program where you require devs to pay $10k and then go through a certification process, which allows them to ship native apps. Basically its the XBox model. Indie devs use managed code. Apps that are willing to go through the more expensive process get native access.

Why? Native apps introduce a bunch of problems that are a pain to deal with. For example, there a bunch of security issues and stability issues that native apps introduce. Additionally you have to target native apps to an architecture. It may lock WP7 into ARM, due to the ecosystem, and block it from moving, for example, to a new Intel architecture.