hmmm - seems bethesda are releasing more stuff to buy on the marketplace.
http://uk.xbox360.ign.com/articles/700/700654p1.html
Here's a few snippets from the above piece...
The post also makes mention of the upcoming downloadable content, The Orrery and The Wizards Tower. Unlike the Horse Armor update earlier this week, The Orrery will add a new quest, rewards and powers for your character. Bethesda is hoping to release it next week for a cost of 150 Microsoft Points ($1.88) on the Xbox 360 Marketplace, and $1.89 for PC.