2 cents from a guy who is not scared to repeat himself.
One profession is geared for PvP and only one, and my freind, you already got it.
What is it about tailoring that tickles your fancy? Mind you I am not putting down the trade, I just am currious.
The Tailoring Pros:
1: Make your own armor
2: Mooncloth(essentaly you can just make cash .... as of now, who knows what the x pac holds)
The Cons
1:The armor you make rocks, till about level 30, when the game gives you a healthy supply of instances that offer items as good if not better.
2:you give up a viable source of cash, selling cloth
As you can see the profession ballances out, but the hoot is that 90% of the items you may want from the job can be purchased(or traded if you stockpile cloth). When you get to late in the game and you want the Robe of the void, you may think of droping mining and leveling talioring to make one, then go back to mining, but overall the profession is great for PvE, but what you give up to keep it is too much IMHO.
Enchanting is your poor choice IMHO, it is a poor choice for a first toon profession, make your first alt a enchanter. While I will not get in to the pros and cons of enchanting now; I will let you know most folks who take it on the first toon are on theese fourms whining up a storm about how they get cheated and it is sooooo hard. Well It is a hard job, and they do get cheated, so do not put your self in a position to be that guy. lastly unless you are a druid, there is not a thing in enchanting that you cannot buy(if you alt is a enchanter he can make the mats for you to get cheap enchants from others, well for a litte while, they are changing some of the Disenchanting rules in B.C.)
When you play on a PvP server, One profession is king and thats blowing up crap. Other jobs are good two, and enginering is not for everybody, but a lock is silly to not take it.
Lock advantages with enginering
1:suplement the warlock's marginal AoE dammage. The ability to stun targets while you get a few tics of RoF or hellfire off is priceless
2: even more CC, net gun is good
3: Mana free Dammage, be it explosives or deathrays extra dammage is good, stuff like the death ray is fun because as a lock you can drain the life of your targets and replace the dammage it dose to you!!!
4:great tastes that go great togather. other classes see this too, but it is just good combos of lock spells and items from the trade. For example, Rogues can be issues on PvP servers, but a warlock with cateye gogles and a felhunter out has a magic synergy and can see tricky rogues/druids from a great distance(it is fun to supprise them when YOU start the fight)
5:landmines!!!!!!
Ok thats it for me:) I hope you enjoy what ever you take, all the professions are fun(Unless it is enchanting on your first toon)