What is GrandCentral?
GrandCentral offers many features that complement the phone services you already use. If you have multiple phone numbers (e.g., home, work, cell), you get one phone number that you can set to ring all, some, or none of your phones, based on who's calling. This way, your phone number is tied to you, and not your location or job. The service also gives you one central voice mailbox. You can listen to your voicemails online or from any phone, forward them to anybody, add the caller to your address book, block a caller as spam, and a lot more. You can even listen in on voicemail messages from your phone while they are being recorded, or switch a call from your cell phone to your desk phone and back again. All in all, you'll have a lot more control over your phones.
Why does Google want GrandCentral? Google said, "We think GrandCentral's technology fits well into Google's efforts to provide services that enhance the collaborative exchange of information between our users."
But how so? Google Talk? Google Click to Call? Google Maps? Google 411? Google Mobile? A Google mobile OS or phone?
Some people feel it is more about leverage phone with social technologies, like YouTube, MySpace, blogging and so on.
See a lot of the coverage at Techmeme.