canadacow's MT-32 emulator (especially the Windows driver version) has fallen by the wayside before it was really usable. Fortunately, KingGuppy has made the awesome "Munt" emulator (http://sourceforge.net/projects/munt/). Browse around these forums for more details.

Also, since you mention LucasArts games, you might be interested in ScummVM. KingGuppy has integrated his Munt code into the official ScummVM codebase, so you don't even need Munt installed in Windows to play LucasArts games using his MT-32 emulation. Also, ScummVM tends to have a newer version of KingGuppy's code in it (although he says he plans to release a new Windows driver version soon).

Worth mentioning is the fact that for most MT-32 MIDI files, you need to transmit a System Exclusive message to your expander for the music to play correctly. As far as I could test, sending a SysEx to Munt from an external application like SendSX makes the emulator crash.

I've sent SysEx data to Munt using Cakewalk SONAR 4 and it works fine. I tested using some Quest Studios MT-32 MIDI rips from Firehawk, with included .syx files.