During the promotion, any variety of Jamba's steel cut oatmeal is available for $1 (regularly $2.99 at my local Jamba Juice) on Wednesdays. The promotion runs through December 26, 2012.
It looks like Jamba is hoping to draw in customers during the cold, winter months with some hot oatmeal. Fall and winter are generally a down time for the chain's mainstay smoothie business.
You can get more details and check out the list of participating locations on the Jamba Juice website here.