Fizzios comes in three flavors: Golden Ginger Ale, Lemon Ale, and Spiced Root Beer. The selling points they're going with, besides being made and carbonated to order, is that the soda contain no high-fructose corn syrup, no preservatives, and no artificial flavors.
Fizzios aren't available at all Starbucks locations but they put up an online locator so you can check to see if there's one near you. Starbucks is also sampling Fizzio through July with a soda truck. You can find the truck's schedule on the same page as the online locator.
Fizzio is available in Hawaii, Southern California (Los Angeles, San Diego, Stockton, and Modesto areas), Arizona, New Mexico, Texas, Oklahoma, Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina, Virginia, Nevada, and Utah.