If you're after M9 colours, the Ricoh GR does surprisingly well, depending on the processing you use. My M9 processing tends to be very vivid, and I can match the GR to it surprisingly well. The GR has better recoverable highlight detail than the M9, as well, although its shadow recovery is not quite as good, I think.
The closest I have seen to the M9 is actually the Ricoh GXR M-mount module. Having bought loads of cameras and played with many more, the M-mount module of the GXR has a look that is somewhere between the M9 and film. I shot someone's wedding with the M9 and GXR, and it was difficult to tell the difference between the cameras, particularly since they used the same lenses.