From the Google Commerce Blog
Since we released the first version of Google Wallet, the app that makes your phone your wallet, we’ve made it available on six phones from Sprint and Virgin Mobile, as well as the new Nexus 7 tablet. We’ve also partnered with more than 25 national retailers, and thanks to MasterCard PayPass, you can pay with your phone at more than 200,000 retail locations across the U.S. Read more
Today we’re releasing a new, cloud-based version of the Google Wallet app that supports all credit and debit cards from Visa, MasterCard, American Express, and Discover. Now, you can use any card when you shop in-store or online with Google Wallet. With the new version, you can also remotely disable your mobile wallet app from your Google Wallet account on the web.
I don't see a big advantage of Google Wallet since it's going to be a long time before I feel it's safe to leave behind my old fashion wallet which is still needed for things like a driver's license. I suppose it could be useful if you have a lot of credit or debit cards and you don't want to carry all of them in your leather wallet.