I'm curious about Magsafe2. As a student, knowing that 20% of students on campus (those with Apple computers) use the same charger as me, I find it really easy to borrow a cable for 20 minutes to get charged up for class. I'm guessing Magsafe2 isn't compatible with traditional magsafe.
Update: It's not but they sell a $9.99 adapter "The MagSafe to MagSafe 2 Converter allows you to use the MagSafe connector on your LED Cinema Display, Thunderbolt Display, or MagSafe Power Adapter to charge your MagSafe 2-equipped Mac computer."
It looks and I would guess it would be magsafe 1 compatible. Maybe it has extra features or power to it. Pretty much any MB* can be charged on any power adapter albeit slower (or not at all if heavily using it).