I spoke with Raffi at Full-Race and he says Borg Warner is still tweaking the aero on their turbine wheels and "They have made some considerable increases from the first gen 7163 that was unveiled at SEMA". They're hoping to finalize the design and start production by September meaning we may see these second gen turbos by the end of 2012. Early 2013 would be a safer bet tho.
Also, I came across this on MotoIQ:
Team America World Time Attack - ARK Design's BNR32 Skyline GT-R Part 7
Looks like Borg Warner is working on a quick spool valve for divided manifolds based on the location of the "secret parts" and the lever arm extending from it.