I could be wrong about this -- if so apologies in advance, but the way I understand it is that while the mtb 9 speed rear shifting will be fine, problem is with the front. Mtb front shifters (both the shifter and derailleur) are incompatible with road cranks, due to a combination of chainring sizes (requires different der. cage shaping) and throw between chainrings (shifter problem). Apparently you can 'make', say, an XT front shifter 'work' with a road der./crank, but it'll never be quite right. Pleasecorrect me if I'm wrong, as I'd love to use XT dual control with a (flat-bar) road drivetrain!! Anyway, that's the reason for the separate SL440/660/770 series of shifters mentioned elsewhere in this thread.