Why not single chip ?
 

Could someone with the technical background please explain to me why top-of-the-line digital SLRs can shoot 10 megapixel or larger photos with excellent color at frame rates of up to 9 FPS using single chip blocks, while $10,000 HD camcorders can't shoot 1900x1200 at 60 FPS without three chips ? I realize that the RED and SI-2K cameras use single chip technology, but why haven't the major camcorder producers jumped on board yet ?

In two words, chip size. The DSLRs you mention have far larger chips than the average $10,000 camcorder you talk about, and generally use either prime lenses or zooms with much lower ratios than most video cameras - hence keep a reasonable size/weight/cost. Build a camcorder with a single chip of the size of that in a DSLR, and with the features most people expect in a video camera (such as at least 10x zoom) and it would be big and expensive. Simpler generally to use three smaller chips.

You can get small cameras with single chips - but they are inherently less sensitive than those with three chips of the same size (all else equal).

I have heard it is a factor of heat as well.

The DSLR chips generate a lot of heat and in a constant video type application would not be easy to cool.

Please correct if I am wrong.

Convergence!

We may see 24fps DSLR offerings from major manufacturers in the next few years.

Another factor is shutter speeds. While sometimes you may compensate for low light conditions by setting shutter speed fairly low on a still camera, it usually just wouldn't be practical with a video camera.

You could say they're already here in the form of RED and SI 2k both of which record RAW.

and both have problems dealing with the heat.

I wonder if the forthcoming UHD cameras will be single or three chip?

Probably a very advanced single to follow the Red groundwork.