If anything I'd say this move makes Denny more expendable. Not that he's going anywhere, but I just have a gut feeling he's on thin ice over there. He's been doing a lot of complaining lately and not much else.
I think Carl can win a championship with JGR though, I'm just not convinced they have the equipment to do it yet. I think if they can level out the HP disadvantage the Toyota's are currently dealing with, then he will become very formidable. He's shown he can win on any type of track.
I also agree with @
ted@economy in that they need a big name crew chief. If they can bring in a guy who knows what he's doing then they could be instant contenders ala Harvick and the 4 team. Of course on the flip side, we've all seen the growing pains associated with starting a brand new team. It won't matter how good the driver and CC are, if the crew can't remember to tighten the lug nuts or take the bean bags out of the car, then it could be a long season for Carl.