Sep 2nd 2010 6:38PM Professions? Auction house?
Run a GDKP on all content you know. You'll make ez money as a carrier, and it's quicker than grinding mats. Some of these raids can be painful carrying un-geared alts (or more surprising, inexperienced mains, but it still happens, though you gotta wonder where they got the gold). A singular icc25 GDKP with some heroics can net you 10Kg after the pot split. Even a regular TOC25 can net you 2k gold.
Selling titles and mounts from Ulduar - the 10 & 25 drakes, Mimron's head, Starcaller or other titles - these are big sellers, and still have a very high demand. Get a good team of regulars you pull these with, and you'll get a reputation and a waiting list. You can advertise the services on wow's realm forums, to get clients, and Blizzard supports the GDKP and title selling practice. If you're consistent, you'll end up with a large enough waiting list that peeps will bid.
If you're regularly dropping the LK in icc25, bring in a couple Kingslayer title buyers, for 25K or more each. Guilds are pumping up their guild banks doing this. That won't profit you directly, but it sure makes raiding cheap when your coffers overflow.
Grinding mats/professions right now makes no sense to me - the real money is in raiding, because the only thing of any lasting value is the achievements.