It looks like those Xbox LIVE individual music stores that have been teased since the last update are finally hitting today.
Personally, I find these to be welcome additions. As someone who purchases a lot of Rock Band DLC (yes, I'm guilty of spending way more money than I should), not having to pop the disc in first to browse, preview, and download the content
Photo Gallery: (15 images)
Click to zoom - browse by swipe, or use arrow keys
can cause it. You can fix it by adding *.disqus.com to your whitelists.