Majic:
When the .41 Magnum was developed the principal advocates (Bill Jordan, Elmer Keith and Skeeter Skelton) wanted a .40 caliber cartridge with non-magnum performance to be used in a middle-framed double action revolver for law enforcement officers. Jordan and Skelton were experienced lawman themselves, and they saw an updated .41 Colt as a better choice then either the .38 Special or .357 Magnum, which were "the" police service cartridges at the time.
Smith & Wesson were very interested, but they knew that a true .40 caliber round could fit in a Colt Python, and they didn't want to give their arch competitor any openings.
So they upped the bore size to .410 rather then .400, which would insure that Colt couldn't use it in any guns they were making at the time. But this forced S&W to chamber the new cartridge in their N-frame, so while they were at it they raised the performance to Magnum levels. This turned out to be what Jordan, Skelton and Keith didn't want. In private, they were not happy campers.
Meanwhile Colt was working on an update of the old .41 L.C., but they didn't do anything with it. Unfortunately Colt's management was brain-dead at the time. For their part, the .40 advocates made a mistake in working with S&W instead of Colt, but then Colt might have not been interested at the time.
The .41 Magnum is a good cartridge in its own right, but it is not a particularly good one for law enforcement.
It is unlikely they're be any further development in this direction. The police have gone to automatic pistols chambered in .40 S&W or 10 mm Auto. The .40 S&W offers performance that is close the what "the advocates" recommended in the first place. What I think we may see (as we have already) are revolvers chambered for the popular .40 automatic cartridges using 1/2 and full-moon clips. It is not necessary to shorten the case of a .41 Magnum to "special" length to obtain lower velocity. One simply has to lower the powder charge.
I had a number of conversations with "the advocates" at different times. All were disapointed at the way things worked out. Of the three, only Elmer Keith personally used the .41 Magnum to any degree, and of course he still prefered the .44 Magnum.
So it goes ...........