Hello Martin Maier,
Thank you for contacting us.
Indeed, there was a special promo offer but it was valid for active MSDN subscription holders only and expired on July 31. The promo license was identical in functionality with our WPF license, but offered no dedicated support - just community support. If you are an active MSDN subscriber, please feel free to check out the 'Special Offers' section of your MSDN account for new promo offers.
We appreciate your interest in our WPF controls and would like to inform you that we offer free evaluation copies for RadControls for WPF. Our trial versions are fully-functional and work without license keys. To proceed with the download, you need to log into your account and go to the 'Free Trials' section.
Let me know if I can be of further assistance.
the Telerik team