First, Apple is pushing its green aspects. For example, the charger is smart enough to pull less power once the batteries are fully charged. In fact, Apple claims that it has the lowest standby power usage than any similar charger on the market (more on that in a minute). Also, Apple notes that the 6 batteries that ship with it are able to hold a long charge over hundreds of charges. Expect to get 10 years of use out of them, Apple says. The idea is that users will pull less power from the grid and use fewer batteries with Apple's charger.
Also consider that this is another step towards Apple's making "the whole widget." For example, you can now buy a computer, mouse, keyboard, Magic Trackpad, batteries and battery charger all from Apple. Who says Steve's a control freak?
Finally, let's compare it to a charger I currently own, the Engergizer Rechargeable 15 Minute Charger. When I say "own," I mean "despise." Yes, it charges batteries in 15 minutes, and they'll hold that charge for almost as long! It's also huge (it uses one socket and covers the other) and heats up like an iron forge. For $32 it ships with 4 batteries, compared to the 6 Apple gives you for $29.
Yes, it's a battery charger. But it's also been infused with Apple magic.