If I could make the move to a '15 and a hawk camper, I'd get right to it.
I drive a classic (old style) 07 1500HD 6.0 and love most things about it. What would I change? 4wd would be nice but I get by alright with 2wd. I don't really care for the 6.5' bed but parking is easier. 3.73 gears aren't ideal. Gas milage? Hah!
Buying into a new '15 truck would afford me to fix these "issues". I could order one with 4wd, a long box, which in itself would be great but would also help with the fuel range and being a 2500 I would get the 4.10 gears. I'd still have the 6.0 gas mileage I have now but I can live with that over the issues of diesels (I also have a GM 6.5L and a duramax). I don't generally drive half tons, the bit more fuel far outweighs the lighter components and these hybrids/6 cyl turbos/engine fuel optimization tactics are too complicated for long term ownership IMO.
I've also been looking at and trying to find a pop up truck camper which I am not too picky about, get out of my current travel trailer.