I think Triple H will beat Lesnar & Punk will remain Champion until the Rumble.
I think Punk will be champ come the Rumble, but will drop it for a bit between then and now.
Not sure whether it will be tonight though.
Can't see any reason to give it to Big Show (personally, can't see any reason to even have him competing for the belt, but I've never been much of a fan).
And since Cena is surely going to win the Rumble to make the rematch with Rock for WM, I think it would work better for the storyline if Cena hasn't held the belt for a while.