They're going to take their time getting unstuck. From space.com:

"A note to all you Opportunity fans: Get used to the current scenery, because we’re going to be here awhile," said Steve Squyres, lead scientist on the Mars Exploration Rover effort at Cornell University in Ithaca, New York. "We are very optimistic that we’ll be able to get out of here, but we’re really going to take our time doing it."

Squyres said the first rule in this case is "do no harm" – and that means don’t rush anything.

"We’re going to take lots of pictures of all the terrain around the vehicle, to get a very complete picture of the situation. We’re going to do lots of testing with the rovers that we have on the ground to simulate the situation on Mars. This testing will be aimed not just at finding a plan that will work, but at finding the very best plan that will work," Squyres explained in a Cornell rover web site.

One possibility is trying a number of small maneuvers with the robot at first. That information-gathering could then lead to even more testing.

"All of this is going to take a lot of time. But this is a very precious vehicle up there, in excellent health, and there’s no reason to rush anything," Squyres said. The main message now, he added, "is to be very, very patient."