If I had to realistic though, I would have to say that we'll (sadly) stay the same, benefiting from nerfs of others.
But if that blonde buxom bruiser doesn't get a nerf, I will use someone with a crouch that invalidates half her moveset as a secondary. She's just so... unpunishable, no matter who I use.
Marth, Lucina, and Samus will probably be buffed. And maybe some wii fit trainer love.
And for those Wii U owners, have fun with miiverse. Be sure to screenshot some marvelous portraits of the king (and also wario, meta knight, charizard, and wii fit trainer) while you smash about.
And in response to grabs, pretty sure charizard is considered the best of the heavies when it comes to grabs. Sadly with that beautiful grab range, he has no real combos off them (he can act out of his back throw very early though), but they give him good control of the stage and can lead to an edgeguard situation where he can rack up some damage with flamethrower. And down throw is a kill throw, though it's not ness back throw insane. So... now you know in case you fight a charizard that knows what he's doing.
EDIT: 1.0.8 gave Charizard a combo throw in his down throw and up-throw is now a kill move. Huzzah! Now if only King Dedede got some better frame data...