Mining nodes have just completely dried up in Outland. I hear the same has happened in Northrend. Mining takes a lot longer to level than herbalism because mining nodes take a lot longer to respawn. See the comments for mining nodes on Wowhead: http://www.wowhead.com/object=181556#comments:40
Just try collecting enough Khorium ore for the epic engineering mount. You're lucky if you get two Khorium nodes an hour.
I was in hellfire the other week and I can share in your frustration.
I needed 300+ ores for leveling blacksmithing and the zone was free of miners (I always /who the zone and check armory for profs on any players present and log an alliance alt and do the same) and I really struggled to hit that target.
Hoping nagrand is a little better as it's ada ore next...
On my server at least, prices for FIO are soaring, and the veins are no where to be found. I came across one and was surprised to find it was already in use, up out of the ground sprang a level 61 Hunter and a 74 Death Knight, both undermap botting. The possibility of this being on your server is high.