Windows 7 Taskbar: Some Beta to RC Changes

There have been some minor updates in the Beta to RC timeframe with regard to the Windows 7 Taskbar APIs.  Just a brief reference:

1. The upside-down bug with custom thumbnails and live previews has been fixed.
2. There’s a new interface, ITaskbarList4, which extends ITaskbarList3 with the SetTabProperties method, which allows customization of when to use the thumbnail or live preview provided by the main application window and when to use the thumbnail or live preview provided by the individual tab. (This is useful for applications like Internet Explorer, which might find it easier to render the main frame if a preview for the currently active tab is requested.)
3. Applications can opt out of pinning to the taskbar (which, incidentally, also prevents them from being pinned to the Start Menu). This can be done by adding the PreventPinning shell property to the application’s shortcut, or setting it on the window’s shell property (through SHGetPropertyStoreForWindow). Alternatively, the new STARTF_PREVENTPINNING flag of the STARTUPINFO structure allows the same to be done for a newly created process.