The latest issue of Leica Fotografie International (7/2003 October) has a piece on the new 90mm Macro Elmar M. The lens comes with a pair of eyes something like the DR Summicron. These eyes attach to the camera lens mount and the lens then attaches to the mount on the eyes.
According to the magazine the lens will go to 3:1 and is expected to cost 1200 Euros.
The same magazine also has an interesting piece on the new CM.
I agree that macro photography belongs more in the SLR category. RFs weren't made or marketed with that in mind. Shades of the old systems made for the screw-mount Leicas. And why should the close-up "eyes" be a separate purchase from the lens? If they are needed to make the lens operate properly, they should be part of the lens purchase. The old dual-range 50mm had such "eyes" for the closeup end.
Buying an SLR and a macro lens (such as the very well-regarded Tamron 90) would probably be cheaper and give equivalent results. Or might I suggest a Minolta and the AF100/2.8 macro which is really, really sharp.