Have you kept in touch with your dealer? I was told the same thing and got a call the following week that the tank was in. I have been following the same service writer to this third dealership since I bought my car new in 06, so maybe he had something to do with the quick turn aroun . Good luck.
OP, I'm chasing a similar problem with my 06, under WOT the car drops to idle, doesn't stall just stops going, let off the pedal it returns to normal and drives fine. I can approach top speed with a slower acceleration and no problems. Stomp on it and it goes momentarily then cuts out completely. The tank was replaced and I had them replace both fuel pumps while they were at it. It's also stalled twice while warming up in the garage. Weird