If the photo is accurate, it looks like 8 or 9 pins just on the side showing. That means there could be 8 pins on the other side as well, meaning 16 or 18 total. Even if the cable has the feature of auto-sensing the cable's orientation upon insertion, as some rumors suggest, we could be looking at 16 or 18 distinct pins, and not just 8 or 9. If the pins are "corded" in various combinations for different functions, this could account for how they can cut back to just over half the original 30 pins on the iPod connector.
Regardless, even if there's an adapter for the new cable to connect to old peripherals, it seems likely that a number of peripherals will either need a re-design or else they will be 86'd altogether.