I have 450 of every profession on my alts (well tailoring is only 437 atm) and now all alts leveling are a mix of mining, skinning and herbalism. So all my toons have the best crafted gear made for them including titansteel weapons, Ebonweave, Epic JC stuff etc. Gives you a big head start - in most cases you are easily geared for Naxx or even Ulduar 10. Also, you can just focus on a couple of heroic instances for each toon to fill the odd missing slot.
____________________________RareTrevor - Feral/Boom
Other 100's - RareBertha (Mage), RareAgatha (Paladin), RareMildred (Warlock), RareGretchen (Hunter)
Others - RareHelga (96 Shaman), RarePearl (93 Rogue), RareEileen (93 Warrior), RareDorothy (93 Priest), RareViolet (93 Monk), RareWinifred (92 DK)
Rarebeast-Feral Druid. and 9 other Level 80+ Rares R.I.P