If you have gold to spend, there is lots of money in making epic gems through JC. A lot of xmuters dump stacks on my server for around 60-90 gold and they resell for 110+. With cata coming out things might change there.

Or enchanting, requires no gathering, and those sell for tons on ah.

Personally hate gathering profs, to much time running and gathering, when ah simply does all the work for you with ench/JC.
Alch and JC are good combo, and enchanting allows you to pick any random other. Maybe JC and enchanting :P