GPU based Render Node/Slave ?

[Headroom]

As it looks right now, almost anyone with a mac is out of luck if they want to work with indigo's GPU acceleration. I really enjoy my current 24" core2duo iMac and was thinking of potentially upgrading to a new 27" i7 iMac some time early next year.
The ATI Radeon 4850 in the newer iMacs is not (yet ?) amongst the supported GPUs. And even if I'd own a MacPro the selection for graphics cards that are supported by Indigos GPU accelleration is rather slim and expensive.

So the next best ting could be a GPU based render node.

Here are the the questions:

Does that even make sense ?
Would I loose some of the ineractiveness that the GPU accelleration offers ?
Are there any limitations in terms of licensing that would prevent me from doing that ?
What is a not too expensive combination that offers a good balance for the Indio Hybrid CPU/GPU render engine -AMD 6 core and Nvidia GTX 260 ?

I am sure I could come up with a few more questions!