Gearing plan for 80

Ok, I just hit 71 and I'm questing just fine with my 4 warlocks. I haven't played for a year and don't really know anything about Northrend.

I currently have 25k honor. My current plan:

1. Buy the 84 resilience trinket for 30k honor when I hit 80.
2. Start buying honor gear/arena gear as fast as possible.

So my question is, where does wintergrasp fit in? And what else do I not know about? I'd hate to buy one thing with honor if there is a wintergrasp equivalent available at the same time.

Also, can I genuinely contribute to some of the world pvp at this level? Something I can do before I hit the upper 70's and start running the regular bg's again?

Four toons at 71st, can take many single 80's.
You can contribute to world pvp at any level, especially with four of you.

I'd definitely go with the 2 min trinket as your first pvp purchase, unless you're human and have that as a racial.

Depending how geared you were, there are Northrend upgrades for the leveling up process.
One of spacegirls (shammy) was a mix of T5 and T6, her first up was at 77th.
The rest of my spacegirls leveled to 70 basically at about WotLK release, so didn't have a bunch of gear and were upped constantly.

I'd personally do Howling Fjord or Borean Tundra, and then the other.
Progress to Dragonblight or Grizzly Hills and then the other.
That way, if a quest is really annoying, you can skip it and not be too bad off, even if you miss anything else in its chain.
The Icecrown quests you'll want to do them all, even if they're painful, because they open up dailies which are very lucrative.

Battleground whenever you feel like it, as a distraction or change of pace.
Most of the gear is 30-40k or so.
Try not to go too far beyond the honor cap, since that's basically wasting honor.
The combo of Strand, Alterac, Arathi, Warsong and Eye marks, can be turned in for honor too.
Prior to 80, I'd just hold onto the marks, until you have 100 of each.
Wintergrasp is worth doing at every opportunity for honor.
At 80, its worthwhile to arena at least 10 games a week, even if you just dance naked and die fast.
The arena pts + honor pts is basically a very cheap piece per week.

I can't even imagine the lag taking my 5 guys into wintergrasp lol :)

I really don't mind dropping down to trips/duals/singles as I really like pvp.

My gear right now is pretty much all green. Affliction warlocks level so easily that it hasn't been a problem. I just run through fields of things dotting everything. Now that dots crit, the mobs split between my guys and I end up getting healed for more than I take.

Oh, is it still worth going tailoring for epic gear in the end? If not, I'm tempted to switch all 4 to engineering just for fun stuff.

Also, I've made the run to Dalaran, connecting all the flight paths, so I have a bit of mobility for getting to wintergrasp when possible.

The tailoring epics are BoE, so you don't have to level tailoring on each toon, unless you're specifically going after Lightweave Embroidery.

Engineering is getting a bunch of nice boosts next patch, so it's definitely worth considering.

I play WG a lot with my 5-boxing groups...it gets laggy, but still playable IMO.

Personally, I'd save the 30K honor for one of the PvP set items, and got for these trinkets which are purchased with WG marks:
Platinum Disks of Sorcery - 25 marks
Titan-forged Rune of Audacity - 25 marks

Cheers,
S.

Get the rune first as it acts as a pvp trinket as well and should be the first thing you go for.