In case you weren't aware, Age of Empires Online is shaping up to be a deeply different kettle of papyrus from the original Age of Empires games. That should be made clear by the following dev diary, explaining how MMORPG-style loot and equipment work in the game, as well as where you'll be getting it from and how you can trade it with your lovely friends. Ooh, it's lovely and friendly, this online world of ours, when it's not busy being mercenary and horrible.
Probably all this video will do is pique your interest for some more robust analysis of Age of Empires Online. If that's the case, let me direct you to Total Biscuit describing the game and his time with in in his inimitable, amphetamine-laced style.
Also, here's some information on how its pricing plan will work. Worth reading, seeing as the details on everything from premium packs, pro packs, "booster" packs and "extras" packs should give you an idea of precisely the game they're trying to make here.