Yes it does, and the link to it is built right in to the Audition interface. I don't have it in front of me right now, but it's in the upper left hand corner of the GUI, and there are a couple of tabs to choose from, one being News. It's called Resource Central, and there are loops, sound fx, and music beds.
You're right Durin - I was thinking Soundbooth, but you can still get everything right from Audition, by opening the Help pulldown, then clicking "Sound Effects and More". This takes you right to the Adobe download site - you log in, and there you go. Actually I like this better than having the Resource Central panel taking up room on the interface.