Some time ago, the dev team discussed a shuffling of our repository structure. The line and difference between [current] and [extra] is blurry and confusing, so we're going to do away with that line and change how these things work.
The new [core] repository will contain all essential packages for getting a system up and running. In essence these packages are the core of Archlinux.
Everything else from current that is non-essential will be moved to [extra].
For now, we will be stopping the mirror syncs for a while so we can move everything around. Don't fear! Your mirrors aren't broken or out of date!