It's kind of amazing to realize that WoW turns 10 tomorrow, and we get Molten Core and Southshore vs. Tarren Mill to celebrate. The fine folks at Wowhead have a detailed guide to the anniversary for you to look over. You can get an epic ilevel 640 helm, a weapon glow effect, mounts and pets from MC, titles from the new battleground, and of course the celebration package in the mail with an item to boost your reputation gain with Warlords factions.
It's not often that an MMO gets to be this big this long. We even got to see 10 million subscriptions for the 10th anniversary. Party time!