Could be all of things mentioned, MAF, overboost fuel cut etc..MAF's seem to give different symptoms when they fail but mine was more of a misfire than like hitting a wall on boost. I did have the boost solenoid stick a few times and that was like hitting brick wall, it seemed to happen overtaking when I was really hammering it but then would almost instantly fix itself. Incidentally if the MAF is knackered it won't affect your boost so see what your gauge does when it next happens, if the boost doesn't dip it's not the MAF, coil paks or plugs.