I see that the new Community Edition of the 4.0 CMS will support Windows Live Id's. What is the upgrade path of current 3.1x sites? Will my users just need to change their profile, or will they need to register all over again? I see the use of the Live Id to be a huge improvement. With a .Net user group, we all have a Live Id for all of the Microsoft sites (msdn, codezone, codeplex, etc).