no offense, J-Diggs is the shit, but Dre was not the first person to drop 2 albums on one day. Insane Clown Posse dropped Bizzar/Bizaar albums 10/31/2000. If you count how many albums their label dropped that day was 3 (Bizzar, Bizaar, and Twiztid's "Freekshow")...
personally bad idea for sales, who is going to buy 3 albums in one day?