October 6th was the big launch day for Windows Phone and there are many great posts on the new devices available. I have more info on devices here. As background, since the initial release of Windows Mobile 6, the Windows Mobile team has progressively enhanced the Windows CE 5 operating system that powers the Windows Mobile platform. You should expect better application stability, much more virtual memory available to running apps, and faster execution. Here is some additional background for developers interested in developing for the Windows Phone:
Both Native and Managed code developers can take advantage of the new Gesture API to add panning and flicking to their apps. The built-in physics engine allows developers to add smooth, finger-friendly scrolling. The Gesture APIs are available in C++ as part of the Windows Mobile 6.5 Developer Toolkit. Luckily some great folks (Maarten Struys, Alex Yakhnin and Ron Buckton) created a managed wrapper available here. There is a code sample also available here.
For web developers interested in building data snacking applications, Windows Mobile 6.5 introduces Widgets as an alternative to C++ or .NET development. Here is my blog post providing links and information regarding Windows Mobile 6.5 widgets.
If you need a quick checklist on setting up a Windows Mobile development environment please check out my blog post here.