I've heard it's a July fishery, not much happening in June. I've also heard that it's very, very French. If you don't speak French make sure you have good accomodations. Gaspe is much friendlier to us non-French speakers, though I have ordered "pizza" and gotten "poulet" a few times. It's all good, the fried chicken is awesome up there.
Regarding the fish, I've heard they're quite something. Tails like a canoe paddle and all that. I know a solid-good salmon fisherman who lost three fly lines in a week up in the canyon water. I'd love to fish it some day myself, I like those big bad rivers. Perhaps somone on the list knows of a good outfitter.
Small flies is the word too, # 8's and smaller.