The new bread will be joining a line up that includes 9-Grain Honey Oat, 9-Grain Honey Wheat, Italian, and Italian Herbs & Cheese (plus Flatbread, Hearty Italian, Monterey Cheddar, and Parmesan Organo in some Subway stores).
It's unclear whether the new garlic bread is the "Roasted Garlic" bread offered at some Subway stores (which looks like the picture above and is essentially Subway's Italian bread with roasted garlic topping) or the garlic bread option tested as far back as 2006, where a buttery garlic spread was squeezed out of a tube onto regular Subway bread prior to toasting, or something else entirely.
As with most limited time items, if the bread does well enough, it's likely to end as a permanent option. According to USA Today, Subway plans to regularly introduce limited-time bread offers to see what sticks.
8/27/13 - Updated for clarification
