Once again, procrastination pays off.
A slashvertisement recently pointed to a spam article extolling the virtues of a particular disk recovery service with the summary hinting at "insights into disk recovery techniques". The article itself got ripped to shreds in the comments, but someone did post a link to a Defcon presentation about disk recovery that I found extremely informative (links below).
I'd put off attempting to recover data myself as, quite frankly, I didn't know what I was doing and because this is the kind of thing you could conceivably only get one shot at doing. After the presentation, I think I've got a better grasp on what's happening and feel like I've got a decent understanding of the drive anatomy. Given the symptoms of the crash, I suspect I can get by with simply cooling the drive and not having to engage in swapping out boards or cracking open the casing. Going to add one of those USB drink coolers and a USB firewire IDE adapter to the shopping list and give this a shot.