In an amazing about-face, Broadcom have released their Bluetooth SDK (Both the desktop and Windows CE versions) for free on their website, all you need to do is provide some basic information to register and you'll receive a download link via email. In many ways the Broadcom stack has always been ahead of the Microsoft version in terms of supported profiles, the real stopper has been the need to purchase the SDK to develop for it.

Thanks to forum member Robert83 for the heads-up!

It will be interesting to see how this affects the balance of stacks on new devices, now that both have an accessible programming model, however each stack is not without it's faults - lack of radio control for Broadcom and fewer profiles supported by Microsoft for example.