Bethesda’s expansion for The Elder Scrolls: Obliviion, The Shivering Isles is now available on the Xbox Live Marketplace. The expansion promises more than 30 hours of additional gameplay for one of the best games on the Xbox 360. The add-on sells for 2400 Microsoft Points ($30), basically matching the price of the PC expansion, which makes this the most expensive downloadable content to date. The download also weighs in at almost a gigabyte, so those rumored 120 GB drives might come in handy sooner rather than later. Still, for Oblivion addicts, this expansion should be a great way to pass the time during the upcoming Live downtime, assuming that you can get it downloaded before the service goes down.