I ordered it from welovemountains.com who were brilliant, they even rang me to tell me to check that I was OK that they didn't come with the bolts as it showed in the picture.
It took a bit of careful adjustment as my Hope floating rotor was rubbing against the edge of it where the red anodised bit is riveted to the braking surface, but the XT caliper has already proven itself to be a lot more adjustable than the Avid Juicy 5.
The biggest thing I've noticed is that the actual brake lever is a lot smaller than one's I've used before, for me it's nearly a 1 finger lever, rather than a 2 finger.
Pics!
Shimano XT M785 Disc Brake by moohcowh, on Flickr
Shimano XT M785 Disc Brake by moohcowh, on Flickr