So, the endless debate: 13" MBP or 13" MBA? I think it has gotten even harder to decide with this later update since the Air has a backlit keyboard now and USB 3.0 (no need for ethernet/firewire/esata). In fact, the only real advantages of the MBP are that it has a faster processor and some upgradability of the components. The MBP is also $100 less, although I would spend that much to get it with an SSD. So... Why are there two 13" laptops? One is heavy and only slightly more powerful, the other is light and thin. Does anybody here have a compelling reason to buy one or the other?