It's no coincidence that my interest in all this has been peaked by sorting out my desk and finally deciding it's time to retire my old external ultrabay, disk caddy, CD/DVD drive and ultrbay diskette drive from my T40 or was it a T23?
I'll be sticking them up on ebay at a know down price rather than let them go to landfill.
So yes, the world has changed it would be cheaper and simpler to build one these days as it could be attached by USB.
Cheaper and simpler.... I doubt that very much.
"Cheapness" comes from being able to produce huge numbers of identical products using psudo-universal interfaces. There are still plenty of Thinkpad specific accessories available (even though the one you desire is not) and they are not "cheap" compared to more generic solutions which can be used with any computer...... even, gasp, Apples!
------------------------------ I don't work for Lenovo