The best way to make money in WoW isn't farming, but mining. Farming does result in the occasional rare or epic item, and I suppose that sorta makes up for the lowered gold from each enemy, but some people I know have never found an epic. I've found 2 farming in Azshara, not to mention like 8 blues. Even so, if I need quick money, mining is simply the best money for the time. Go to Arathi Highlands and go clockwise around the zone along the mountainous border. Make sure to get the ogre camp in the small hill that's west of Refuge Point as well. You can make 20-40g PER HOUR mining there. Yes, it's that bad. People will pay ridiculous amounts for mining items on the AH. Just be careful not to overflow the market. I've never made less than 20g an hour doing that.
Why am I letting my "secret" out? Because I cancelled my account a week ago. Have fun miners.
-Lasereth