In the days of Vanilla WoW and even TBC, Blacksmithing was a gold sink, plain and simple. Almost all of the "good" plans were BoP, and the "good" BoE plans were raid drops. It was nearly impossible to make any money as a blacksmith (other than getting good tips for making enchanting rods).
Now with WotLK, there are tons of plans learned directly from the trainer for items that are basically all BoE, and the items are actually better than many of the quest rewards for comparable level quests. Blacksmithing is almost a necessity for a Prot-spec toon (or items purchased from a Blacksmith).
There are now plenty of items I can actually sell for more than the raw materials would cost me (I mine, so the mats are technically "free" other than the time it takes me to mine them).
I guess Blizzard listened to the complaints that Blacksmithing was totally un-profitable and also had very little for Prot-spec, because now it can be very profitable and has loads of Prot equipment as well.
We also get to socket some of our own equipment as well as create a BoE item that will allow anyone to socket their belt.
This just went from a "meh" profession to a "win" profession in a big way!