Even though I wasn't a huge fan, I owned all Megadeth's albums at some point up til "Symphony of Destruction" which was definitely the highlight for me.  Not long after the tour with Motley Crue, Dave had "an accident" (no details provided) and supposedly fucked his left hand up in a big way.  The message on Megadeth's web site said something along the lines of "Dave suffers serious injury, Megadeth is fucked, blah blah blah..." Check out their web site, I'm sure it's all there still.   Goodbye Droogies.   

Major Serious Update Report:  Dave is back.  Yes, that's right... Dave is fuckin BACK.  Looks like Dave's hand healed up, or he got a fuckin bionic one or something cuz Megadeth has reared it's head again.  Good.  He's got another album and has been touring in support of it since October 2004.  I've seen him in a few appearances, on MTV hosting a memorial type show for Dimebag Darrell and on the Metallica movie, "Some Kind of Monster"... I thought Dave was being a little hard on himself for having been kicked out of Metallica.  So I wrote him and told him I thought he's the shit, he's the real deal and to stand up to the juggernaut that is Metallica, takes a lot more balls than he gives himself credit for.  He wrote back and thanked me for the kind words... hey.... he didn't have to do that did he?  Betcha James wouldn't have.