Recent owner of a P2V+ ver 3.
Very happy with it.
I like the camera on the V+ but since I do video clips and short films, I will in the future try to upgrade it to a better camera.
I have a SONY NEX 7 and I love its movies, and I've seen movies on youtube of people lifting big dSLRs with the phantom. The NEX 7 is much much lighter than dSLRs, so maybe I can hooke it up with a Zenmuse Z15 gimbal to my P2?
Yes the landing gear would have to be redesigned, I'm ok with doing that.
But about wheight and connetions is it possible? Has anyone done it?

THanks

We're going to need a bigger boat...  

The max capacity of the Phantom 2 is 1.3Kg (even the newest version with upgraded motors and props only adds an additional  200g capacity)

The weight of the Z15 is 1.6KG (Z15-N gimbal plus Sony Nex 5)

The weight limit is the biggerst problem stop you from doing that, but I am really interested in the movie you mentioned above.
Phantom with a big dSLRs.
Can you  provide us a link of that?

Video of an old phantom with a chunky big dSLR: