The good people at Brawl Central have been posting updates throughout the day as they watch attendees of the World Hobby Fair play Super Smash Bros. Brawl. Only one thing appeared to be Star Fox related:
“Fox victory pose: Puts hand on hip, is facing sideways and says something (It was unable to be heard)”
I’m guessing it’s something along the lines of “Mission Complete!” like he says in Melee.

I heard that if you use Fox’s Blaster too much, it’ll explode like Diddy’s Peanut Popgun.
No offense, but I highly doubt that. Especially since his blaster is typically used for rapid fire.