Google announced Google Voice based in the acquired GrandCentral service.
Google acquired GrandCentral about a year ago and rolls out to the GrandCentral users a preview of Google Voice.
Google Voice improves the way you use your phone. You can get transcripts of your voicemail and archive and search all of the SMS text messages you send and receive.
You can also use Google Voice to make low-priced international calls and access Goog-411 directory assistance. GrandCentral already offers many features, including a single number to ring your home, work, and mobile phones, a central voicemail inbox that you can access on the web, and the ability to screen calls by listening in live as callers leave a voicemail.
If you're already using GrandCentral, over the next couple days, you will receive instructions in your GrandCentral inbox on how to start using Google Voice.
Via the official Google blog.

The service offering sounds great. Lets just hope Google does not show Adsense ads next to your transcribed voice mail.