This may not directly answer your question, but it caught me quite by surprise.
I recently disassembled a PC Box I had with a Western Digital 4.0GB Caviar HD. There were some files I *kind of* wanted but could go either way on. I plugged the disk into my DP533 via IDE adn booted it up to erase the drive using the Disk Utility in 10.1.
Much to my surprise it mounted on the DT. Disk Utility saw it, but i don't remember if it saw the file format as NTFS or FAT32. I was able to copy the file no problem and they work fine. (most were PNG, .ai files and a few MP3's)
SO.... a firewire drive should function the same I would guess.
I do have DAVE 3.1 on my system for networking, but I don't think that would let the disk mount on the local machine. I think X can do it.
Plug it in, it can't hurt it.