I had to reregister as well, which I did through the Store app.

You will not know you've been unregistered unless you try to run the Store or have a problem similar to amartyn's, but there was a server reset or something (cookie history deleted, change of ISP for enTourage???) not long ago that required most, if not all, eDGes to reregister. As Donna points out, this could cause Adobe issues (in my case it didn't, although I must be near my limit).

The good news is, you only need to reregister once.