Since Emmerald's list (http://www.emmerald.net/) hasn't been updated for all the new shit yet, I've started compiling a wish list of blue stuff, starting with wowhead:
http://www.wowhead.com/?items=4.2&filter=qu=3;minrl=71;maxrl=80;cr=21;crs=1;crv=0#0+3+1
Most of the first page is quest items. I'm assuming I'll run across those in the process of leveling and knocking out quests. As for the rest, a couple sets stand out:
Eviscerator's Leather
http://www.wowhead.com/?items=4.2&filter=qu=3;na=Eviscerator%27s;minrl=71;maxrl=80;cr=21;crs=1;crv=0
Good for bear or cat ferals, and rogues too. These are all available at 78, made by leatherworking patterns from vendors. You'll be able to pick these up on AH or perhaps collect the mats yourself, they aren't too unreasonable. Would work well for those last two levels and/or a starter set for lvl 80 5-mans, and to replace any BC purples you might still have on. There's no set bonus but you've probably given that up for other upgrades already.
The whole "set" will grant you:
Armor: 3028
Agility: 450
Stamina: 450
Attack Power: 588
Crit rating: 300
Resilience: 300
The raw mats are:
84x Heavy Borean Leather (504 Borean Leather or 2016 Borean Leather Scraps)
8x Eternal air (80x Crystallized Air)
...
The new lvl 80 PvP gear looks nice too but you'll need arena points in addition to honor. No more welfare purples from grinding battlegrounds. You could get them with the new heroic badges instead, but there are probably much better pieces to get if you're doing that much raiding and heroics already.
I'm still working on a more detailed list as I level and find stuff.