No, the meph quest drop thing has not changed at all. In the past couple days I've found a ton of uniques - including elite. I've found 2 nosferatu coil's, nords truncheon, kira's, and more that I can't even remember.
Big thanks for the heads up on that by the way - I've been playing D2 since release and never new this could be done with Meph (and have noticed significantly better drops doing it this way). The only problem is finding games where someone has defeated meph and he isn't killed yet. Think I'm going to create a Poison/Summon necro to Chaos/WSK with and then bring my sorc in after to hit Andy/Meph.
-Zaral