Don't really know...

what is going on, but we have an 06 5 speed GT, and every now and then, when you are rolling along really slow, less than 5mph, and you decide to kick down on it, the car actually feels like it goes dead for a second, then revs back up. it is really annoying to me, and i don't know if it's the drive by wire system that is supposedly on these cars, or if it's the traction control or if it's the clutch, or what it is, but surely someone on here will know what i am talking about. it is not a constant thing, but it is annoying to say the least...
 
It sounds to me like it is the TCS. I accidently left it on during a 1/4 and it likely would have been my best pass ever, but the TCS kicked in when I shifted into 3rd and my car just died. It felt like it stalled but was still running. I ended up running a low 14, but I was ****ing pissed.
 
The stock tune is to blame. My 05 did the same thing with the TCS on or off. Ford designed it that way in order to decrease drivetrain shock and reduce the number of warranty repair jobs. An aftermarket performance tune will get rid of the laggy throttle.