I've loved Ravenloft since I was in elementary school and got a Ravenloft choose-your-own-adventure style book. (I can't remember the title or really what it was about aside from a vampire bad guy named Erik Blacksteed and the coverart featuring some elven-looking fighter in a red tunic who is -so- not the loser character they stick you with) I really enjoy the Ravenloft Remix posts over at Tales of the Grotesque and Dungeonesque.
I have always thought AD&D was completely the wrong system for Ravenloft.
Don't get me wrong- I love AD&D in both of its incarnations, but the system has always felt like the wrong fit, and did even when I was but a lad.
If I were to do Ravenloft again (unlikely, but not impossible) I think I would go one of two routes:
1. Use FUDGE, since you can kind of do anything with it if you fiddle with it just enough.
2. Use the pseudo-fantasy alternate WoD described in "Mirrors."
The second option sounds more appealing, since a.) the work is already done, and b.) they even have two "dark fantasy" races that are fare more suitable to Ravenloft than the AD&D roster of Tolkienesque creatures.
....plus, NWoD had rules for most, if not all, of the necessary creature types... .vampires, Frankenstein-ish monsters, shapeshifters, ghosts, goblins (of the fae variety) and so on.