There's an external that comes with it as well...same as the X1.

The major advantage of having the second one in the media base is that the majority of the time when you're using CD's to install software, rip music, etc...you're doing it from your desk, and you don't have to fish out your external drive. Plus you don't have to pack your drive up whenever you leave, you can just leave it in your notebook bag.

Then again...for someone who's truly mobile (no single place where they use the notebook often enough to justify a port replicator), there are certainly better solutions.