Up until now, Google's Voice service has been a bit of a piecemeal apparatus. You've needed regular land lines, a mobile number or another VOIP service for it to work. Today, if the rumors are true, Google becomes a full point to point VoIP provider.
Techcrunch says that Google is purchasing Gizmo5, a SIP VoIP provider. This is important gap that will bridge two of Google's platforms. Google Voice will obviously now have a mechanism for transferring all the way to your computer or smartphone, eliminating the need for a 3rd party to be involved in the transaction.
It is also an interesting pick-up for Google Talk. Google Talk uses standard Jabber/SIP compliant mechanisms to communicate between nodes. Technically, you've been able to reach any SIP compliant client with voice or video calls right from your Gmail page. With the pickup, you will now be able to make voice calls to POTS phone numbers from inside the Gmail page.
This is even bigger news for companies that might want to join up with their Google Apps program and move their phones to a unified VoIP messaging platform.
This pickup is one that has been anticipated for awhile. At the rumored $30 million it is much cheaper than Google would have had to pay for Skype.
Oh, and one more pretty obvious observation: Skype is in big trouble.