One of the new glyphs to come out in MoP is Druid Travel (mount) form. Yes, you can finally now mount your tank and he can take you around the dungeon/raid as necessary. They can turn into a beautiful Stag mount form. No longer will you need to spend 16kg to buy the 3 person mount, or worry about getting the 2 person love rocket.
Jesse doesn't mention that coming in Panda is new Druid saddles. These saddles will allow you to hop on the back of a druid in bear form. Similar to the Horde's Venomhide Mount quest chain, (or I believe there is something Alliance) you'll need to gather the various materials to make the saddle. It's looking like 20x Ravasaur Leather and 20x MoP Cloth.
Unfortunately, they don't appear to have saddles for Druid flight or swim form (yet) or Warlock flying mounts (yet), but this is only phase one of the beta..