I think what happened is that they announced it on blogspot.com and got a flood of new members and hit their beta test limit.
Seems every time I get familiar with and commit to a VOIP technology something better comes along. Not that that is bad in any way, but I now have a bunch of skype equipment which still works perfectly and I use it all, but grandcentral pretty much just made it all obsolete. In fact at this point, I can make VOIP calls to anywhere on the continent using the existing POTS line with NO special hardware on either end of the call at all.
I've been a vonage customer since 2002 and it all still works perfectly - but I'm wondering just how much I still need it. All it really serves at this point is as a busy call forward from roz's phone and a way for a friend to call Canada when he's here. And grandcentral will do that too.