I've done it, to pull the kids for kicks, and it works fine provided there's enough snow, of course!
I have dropout hitches from my mono-wheel trailer, so it was easy for me to attach: I used a pair of old hammock spreader bars that I had sitting around the garage, the holes in which were perfectly sized for the ball-lock pins that are part of the trailer hitch. At the sled end, I just threaded the reins through, knotting them to allow a little slack between the sled and spreader bars.
It was basically pretty straightforward, and aside from the slightly uncomfortable feeling of the sled overriding the bars during a stop, worked fine for a trip through fresh powder to the park for some sledding. Unfortunately, it didn't snow like that again that winter, and I've never used it again since, so my insights are pretty limited.
Chariot has a pretty dope ski conversion kit for it's trailers that might be fun to play, although the simplicity of lashing a plastic toboggan to the back of the bike is pretty irresistible. Tracking on a flat-bottom sled in anything but powder is probably nightmarish, though, so I'd be more inclined to look at something with runners were I to take the notion seriously.