GrandCentral becomes Google Voice. It took less than two years for Big G to integrate this vocal hub into its maze. Eons in this kind of business, and the switch is not even completed yet : only GrandCentral commuters can enjoy Voice services for the moment.
Looks as if Google were preempting some vital territory either ahead of a major move by the competition, or to put some soft flesh on some hardware project to be released in a not so distant future.
The Gphone is already there. It can talk, it has the Latitude to follow you and your pals on the move, it can keep you connected. It can help you reconsider your fling with the likes of Skype.
But Skype appears to be ahead in many ways. And Google (except maybe when it goes 3D) has this tendency to look rather flat, lining up new applications without getting the most of each one, without optimizing the network effect, often turning potential killer apps and killer combos into if not dead ends at least major disappointments.
GV's main feature remains the unified number for voice and SMS : your "Google number". A rather meaningful branding for a key lifetime ID. Google Voicemail (Google Videomail should follow) could come as a booster for Gmail (at last, sonic eavesdropping !)... or even Orkut, if Mountain View hasn't abandoned all hope for its globalization. Google adds several apps generally provided by local loop operators. It's a deviceless device, a virtual PBX, and a potential entry point to the corporate world.
Google brains care less about hardware than about who you are, what you do, whom you know, where you meet, and most of all what you're looking for right now or what you may need sooner than later. Don't be surprised if they ask you to give them your number.