The next paid expansion for Lord of the Rings Online is The Siege of Mirkwood, which will be available December 1st. Developer Turbine has published some developer diaries discussing the new features. For instance, here's a developer who identifies himself as "Zombie Columbus" (Really? That's how you're going to introduce yourself?) on the inspiration for the new skirmish system, which lets players lead soldiers in instanced partly randomized battles.

The initial design that eventually became Skirmishes began during a walk I went on with fellow designer Rhidden, not long after Moria's release. We mused about how we could put a fun sub-game inside LOTRO, using mostly existing tools, tech and art. I was playing a lot of Tower Defense inspired games at the time and Rhidden was interested in riffing on the popular Battle Instances. Mixing those and other inspirations together, we came up with the idea for LOTRO instances where the player would set up soldiers and siege weapons and use them against waves of incoming enemies.

The latest developer updates also include some indecipherable info about the new mount system and some relatively unsexy but extremely practical stuff for how storage will be shared among all your characters.