Wow – this is GREAT! MSDN Channel 9 has a new online training center for you (developers) to learn the Windows 7 APIs. The topics included are multi touch, taskbar, sensor / location, ribbon, shell libraries, background services, instrumentation & performance, installer detection, data redirection, high DPI, session 0 isolation, user privilege isolation and version checking.
There are hands on labs written using managed code (in both C# and VB.NET), native code. Code samples are downloadable. Also there are videos and more resources around each developer topic. The developer prerequisites (with links) are listed at the top of page as well.