Actually, there's a major shift in the industry (to "free to play") that companies have been making. Basically, the company provides an in-game item shop where players can use real money to buy in-game items. These shops accomplish pretty much what this guy was doing, but keep the money in the company purse, and circumvent many of his limitations: there's no need to farm the game when you make the game, and you can sell items which farmers could never obtain.

In almost all cases, it has meant a higher amount of revenue, either for brand-new games or for games which transition to the F2P model or an in-between hybrid model. It looks like, generally, big-name MMORPGs are still starting out with a subscription model, but most games at other tiers are launching free-to-play with an item shop. Lots of long-running MMOs are transitioning to a hybrid model to add revenue to a product from which little is expected but also little is being spent on (just enough money to keep the servers running and keep a slow flow of updates).

I think it would be much harder these days for a player to make money by through farming, except for with the old guard of MMORPGs which still don't have an item shop. I could be wrong, I am not looking at these economies closely so I don't know if the farmers are actually able to provide items / prices competitive with the developrs.