You may get an error if you try to subscribe to the feeds using the links in the left sidebar.
Feedburner, which was acquired by Google a couple years ago, is transitioning their feeds to integrate better with Google products. There are a few kinks to iron out.
Hopefully I can get them working later today.
If you subscribe to the feed through your browser, you shouldn’t experience any problems. UPDATE: There seems to be problems with the browser feed too. Stay tuned.