Conker could make it in Brawl, but he'd have to be on his best behavior. xP The only problem with that is: you'd be taking away from his character. The reason hes so funny is that he's a cute little squirrel that speaks vulger language and likes to get s**t faced drunk.
His only popular games are the ones aimed towards adults. I mean common, do you remember this game:
Probably not... Sakurai won't even allow real guns in the game, so I doubt he's even considered Conker at any point in time. Don't get me wrong though, I'm a huge fan of the games and would really love it if he made it in.
Possible moveset?
B Slingshot
This could work like links arrows. Conker pulls the band farther back the longer you hold the button down (for more distance and power). He launches a stone upon the release of the button.
Smash B Frying Pan
This would be similar to Kirby's hammer, but instead of knockback, the opponent is temporarily stunned. It can be sweetspotted to allow fire damage also.
Up B Helicopter Tail Thingy
I didn't just make that name up, that's actually what he calls it in Bad Fur Day. It probably wouldn't do much damage or knockback, and therefore would be used more as a recovery move instead of an attack. Alot like DK's Up B.
Down B Dynamite
I was debating between this and his Ground Pound-esque move, but I decided upon this because it's much more unique. He could plant a bundle of dynamite on any surface. It remains there until you perform the move again, where he'd pull out a plunger and press down on it to blow up the dynamite. It wouldn't be as powerful as a motion sensor bomb though, since you can detonate it at any time.
Taunt
Pops a cigar in his mouth, pulls out two tommy guns, and shouts "Come and get some you mother ******s!" JK