They are similar, but there are two differences. There is no way to go through the dark portal to the outlands, and we can't get to the WOW TBC Gold level 70 zone until TBC is available. The two new races, the talent changes as well as new professions and exciting features make this pre-patch extremely popular. There is a lot of prep work and new things to come out before TBC is published.
I was not able to pull this many packs and manage them as efficiently However, I remember farming ZG trash with my mage and making decent gold cheap Burning Crusade Classic Gold pulling just a few packs at a go and doing it the old fashioned kiting method of blizzards.