Well, the car has been running fine otherwise. It was pretty hot today (mid 90's) and I had been in bumper to bumper, stop 'n go traffic for about 20 minutes.
After I got past the choke point (an accident all the morons were slowing down to gawk at), I kicked it and felt.....NA for a moment. Then, I could feel boost started to build and finally I was accellerating harder but nowhere near how it feels normally. After the car was moving for a while again, it started to get better and more responsive.
When I got to where I was going, I parked in the shade and left the car there for about an hour or so. When I got back in the car to leave, it felt fine again. With no vacuum/boost leaks and a 2-month old WGA and the car running fine otherwise, I have to assume it was heatsoak.