Interesting pictures and ideas but no-one is really putting any emphasis on the "compounding" part of the 2014 turbo setup to coincide with the rules.
There needs to be room for the gearbox from the drive of the turbine wheel to the crankshaft. A turbo compressor/turbine can spin up to 250,000 rpm so there needs to be a gearbox/clutch to gear the turbo rpm down to crankshaft rpm otherwise the crank would stop the turbo from spooling up and breaking the boost threshold considering the motor rpm limit is set at 12,000 rpm for 2014.
This is a truck compound setup and I dont think they will run with a 2 turbine setup, they will still probably compact it into 1 unit to save weight.
I think they will hang the turbo and gearbox at the the rear of the motor to connect with the crank at the rear, and dont forget the electric motor for the pitlane and KERS. So they might use the same DC motor for both and connect to the front of the crank or they could compact it all at the rear as it says in the rules.
Either way the compound effect can save around 10% in fuel efficiency and give around an extra 50hp for free over a standard turbo setup.