First is a larger battery. Apple proudly notes that the MacBook will give users 10 hours of battery life. The feat is accomplished, in part, by a slightly larger and heavier battery. Despite having the same model number (A1331) as the battery found in the unibody MacBook that was refreshed last October, the current one is 7.5 grams heavier and provides an extra 350 mAh of power. In fact, it's the same 63.5 watt-hour battery as the 13" MacBook Pro.
Also new in this machine is audio and video out via the Mini DisplayPort, which is a small but very welcome change.
We enjoy the iFixit teardowns, but always wonder...who puts it back together?