Well, I bring this up for two reasons. The main one being if Notch is every going to add a survival mode, he should probally consider the atchuall size of vains of metal.
Well, I figured I'd share something I found on a map I know was generated naturaly.
I used osici's map editor as a map and saw little streaks of yellow on the map. I walked there on the real game and started to dig. A few blocks down we hit gold....
We basically hit a stetch of gold that went all the way down to the bottom of the map over 25 blocks below and was huge.