Matt, indeed your understanding is correct. All customers with an active ASP.NET RadControls Subscription will receive complimentary licenses for RadControls for WinForms and Telerik Reporting.
Robert, there is no need to purchase any upgrades. The RadControls for WinForms license is already added to your account. Telerik Reporting will be officially released on April 23 and will be automatically added to your account as well.