If you need more incentive to sign up for PDC now Microsoft has announced that they will be distributing "the bits" on an external USB drive. There will be some software that will be available in a CTP or beta version but there is other exclusive content.

There will be many things that are only available at PDC including the ability to interact with the people who are developing Microsoft's cloud and Software + Services offerings. We are also hearing that we will be the first to get the pre-beta version of Windows 7.