See for what ever reason BM have decided not to fit such in the new X/R.
When you have cylinders sticking out the side you've got more room to play with, maybe?
I imagine there's a bit less space in a straight four for that bloomin' leccy motor in the head. Crazy, but mighty impressive.
I daren't think of the cost if (when?) it goes wrong. Normally these things are driven mechanically or, like Andy says, by some fluid, and that's something you can look at and say 'the seal needs replacing', 'the bearings are worn - replace them', etc. Electricity is a step beyond - it works or it doesn't. Maybe it's a replaceable part - a new leccy motor every 30k or something. Or there's a failsafe position for the pins.
Anyway, Stevie is going to give it a thorough test for us.