I know I didn’t dream this, but I can’t find it at all! It is killing me, I feel like something this hilariously and accidentally prophetic would be easy to find on the internet...
EDIT — I've not found the video (he DEFINITELY said it on camera because I HAVE SEEN IT) but searching again I found this BBC interview which seems to be erroneously dated as 2014 (which may be when it was archived or something):
Simon, you rawked in Shaun Of The Dead. Any plans to shoot off to America, sell-out, and do a big action film?
Simon Pegg: Yes.
Edgar Wright: We want to do an English action film.
SP: I would love to do something in America because the resources are obviously there and production is more prolific over there, but I don't think going over to America for the sake of it and being in anything is a good step. That's not really a move forward. It's more sort of going over and living the dream a little bit. But, yeah, sure!
EW: As long as you don't end up playing second fiddle to Chris Tucker or someone.
SP: If it meant a toss up between doing our next film and being in Rush Hour 4 or Tom Cruise's team in Mission: Impossible III... I would definitely do Mission: Impossible III [laughs].