The other day I announced the latest upgrade to SilverFast Ai 6.5. One of the new features is the ability to scan a color original and as part of the scanning processing do a controlled conversion to B&W either 8 or 16-bit grayscale file using a utility to adjust the color interpretation with a 6 color Channel set of slider controls that are interactive with the preview of the scan output.
I would assume this capability is/will be in the version 6.5 of SilverFast DC (digital camera raw conversion) so color captures in Raw can be directly converted to B&W with 6 Channel color adjustment interpretation.
I realize you are not a Lasersoft SilverFast user/fan, but for those who want B&W from color this is a direct and efficient method.
A somewhat similar utility is also included in Apple Aperture 1.5, but I have not checked out the latest iteration of LightRoom as yet but would be surprised if color compensated channel adjustment is not also included considering a new color> B&W utility is also a feature of Photoshop CS3.