Went to a class a couple days ago for work (john deere), to learn about 2012 model changes, updates, fixes, and whats new on the commercial zero turn mowers. (i'm a lawn mower tech)
One thing that really perked my intrest was the new EFI engine. It was released late last year in limited numbers, and this year will be the first full season. I read about it a few months ago and had been waiting to see one. What makes it so cool, is its full closed loop! The injection system is built by delphi. Has a TPS, 2 injectors (air cooled V twin engine) MAP, oil temp sensor, and a 4 wire heated 02 sensor. It also no longer uses magneto based ignition coils. It has two coils (coil near plug style) and uses a crankshaft position sensor. The ECU controlls ignition timing and spark advance as well as fuel. It goes closed loop at about 110*F oil temp (since there is no coolant) The engine however still uses a governer, so no IAC. It has a electric fuel pump, and fuel pressure is 39 PSI!
Another cool feature, is there is also a diagnostic plug and a live connection can be made to the ecu with a laptop, however you can only connect with JD's software, but its the same software used to connect with any peice of JD equipment. Once connected you can read and delete DTC's (diagnostic trouble codes), and moniter and record live data from all sensors. There is a "check engine light" on the hour meter, and it also has a self diagnostic feature. Turn the key on-off-on-off-then on and leave it on and the light will flash the code. (my wrangler does the same thing...lol)
If anyone wants to google them, its the Z925A EFI.

Another cool fuel injection system is on the 825i gators. These have a inline 3 cyl engine made by cherry. This little puppy has it all. Sequencial multiport injection, DIS, all the sensors you would find on modern mpi engines, DOHC, 4 valves per cyl, 50 HP. This is a hot little engine, makes these things scoot! It will wind up to. You can floor it and it will pull all the way to 6000 RPM!
Funny thing about this, is it uses a OBD2 diagnostic port. However, even though a common scan tool can plug up to it, it can not connect. Uses JD's code and only JD software can connect.
Now thats a ecu I wish someone could hack, I think it would be sweet to put a tiny turbo on that engine, and then do some tweeking of it.