I think it'll go to Cam, and I think it's deserved unless his play really falls off these last few weeks.
I've said this before, but I don't think the stats, especially with regard to efficiency numbers, tell the entire story on Cam. He makes plays. He isn't holding onto the ball to save himself from an incompletion. He gives opportunities to his sorry group of receivers rather than taking negative plays. The receiver drops get counted against him, but that doesn't mean he's not making the best play if he's avoiding sacks and bad rushes. QB sacks taken is an underrated stat, and I think bare completion% and passer rating can be deceiving without context.
He's scored 35 touchdowns overall (28 pass; 7 rush). Palmer's got 32 TDs. Hard to argue against either, but I'm giving the edge to Newton. Done it with less.