Right now I have a GS-500, the image is pretty great and once in a while, when the lighting is just right, I can get a fairly shallow DoF without any adapters. I think somewhere down the line I'll be purchasing a new camera and will spend anywhere from $1600 - 2500 on it. The question is, are there any HD cameras capable of shallow DoF control out of the box? If not, what's the cheapest (other than DIY) solution to obtaining an HD camera with DoF adapter?

Canon EOS 5D MkII will give you 35mm DOF out of the box.

but I'd like XLR inputs, and a full size camera body, a video camera

For $1600 - $2500 no... that's if you mean shallow like with an 35mm adaptor or 5D II.

Any camera with the kind of shallow depth of field being discussed will require a selection of lenses on top of the body, not to mention accessories that will make this kind of shooting easier (follow focus, outboard monitor etc). That's going to be a tough figure to hit for a self-contained system.

Right now I have a GS-500, the image is pretty great and once in a while, when the lighting is just right, I can get a fairly shallow DoF without any adapters. I think somewhere down the line I'll be purchasing a new camera and will spend anywhere from $1600 - 2500 on it. The question is, are there any HD cameras capable of shallow DoF control out of the box? If not, what's the cheapest (other than DIY) solution to obtaining an HD camera with DoF adapter?

The GH1 is coming out from Panasonic soon. It should give a roughly equal DoF to 16mm film, has interchangable lenses, and costs $1500. You can buy a Juicedlink (my pref.) or Beachtek XLR adapter for $200, or record second-system to a Zoom H4 for $400.

but I'd like XLR inputs, and a full size camera body, a video camera

At the price you want, not even close. Scarlet may be what you want. Looks like a video camera but no sound though. You definitely need another setup for that.

At the price you want, not even close. Scarlet may be what you want. Looks like a video camera but no sound though. You definitely need another setup for that.
What if I buy the Panasonic AG-HMC70U and get one of these: JAG35ST (http://web.me.com/jehug/Adapters/JAG35ST.html) for it?

Is there any reason this wouldn't work / have issues?

With the arrival of DSLR capable of shooting HD video, I am not sure if its worth it to get the setup you have suggested. There are still alot of limitations with a video cam/static adaptor setup (or even vibrating or spinning adaptor setup). You asked for a DOF cam out of the box, there are a few in the market as suggested like the 5D2, GH1 and maybe you can wait for the new Nikon cameras coming out this year and next. From what I have read online, they are coming out with 24p capable HD video cam. But they don't look like a video camera unfortunately.

I am not a professional so I am not sure if there are any video cameras out there, consumer or prosumer level with large CMOS sensor for shallow DOF effect. But if there is one, it will be very expensive I am sure.

For XLR input, you can always hook up a beachtek or juicedlink to your camera. The great thing with 5D2 (with Magic Lantern firmware) and I am sure other future DSLR video cams out there coming along, the AGC can be turn off or reduced to allow clear audio to be recorded into the camera.

Just my 2 cents.