We have done some preliminary testing with the new MBP (we have a 15" model with the 2.6GHz i7 CPU and Radeon 450 with 2GB memory) and results look promising for HDx2. I would however not recommend it for HDx4. While it can record 4 streams of video (ProRes LT) it uses almost all available CPU resources to do so leaving you with very little head room.
It would probably work better with the top of the line MBP (has faster CPU) and/or limited to only record ProRes Proxy. But I am still a bit hesitant to give a general HDx4 stamp of approval until we have tested that model.
Good news is that these new MBPs seem to have improved cooling compared to the previous generation.
Any updates on test results? Are u using IOxT's? And what external drives r u using? And what periferals are u using to for sound in/out? I'm about to buy a new MBPro and I'm waiting to find out more about necessary/devices needed? Thanx.