Yes drift will be a big issue. However the satellite images are from the 16th, which helps a bit. Also gives them 4 days of real drift (ie not simulation) to extrapolate from. So a big job, but not hopeless. Probably learned a lot from AF447 experience.
Can anyone confirm the separation of the 2 pieces? The closer together, the more hopeful I would be. Common to find 1 piece of stuff floating around. But in close proximity would be more suspicious of 1 recent source.
Pingers might be good for another 15-20 days. If they don't find by them it will become grim.