MacBook

The MacBook experienced the largest change in the round of updates today. Instead of continuing the line with plastic enclosures, the MacBooks now, like the MacBook Pro, are housed in an aluminum enclosure.

LED Backlit Display
A feature that was introduced previously in the MacBook Pro, LED backlights in the display allows for instant on with no warming up. LED displays also only consumes about 70% the power consumption of previous CCFL backlit displays.

Glass Trackpad
The new MacBooks and MacBook Pros features a new multi-touch trackpad made of glass. This new trackpad allows for gestures like those used on the iPhone and iPod Touch.  This includes the previous gestures of two finger scrolling, zoom by pinching, rotating, and three finger swipes.  Added, however, is the ability to 4 finger swipe to control Exposé and Application switching.

No Firewire
This update added a lot of features, but it also took one away.  The new MacBooks no longer have a FireWire 400 port.  FireWire is traditionally used for external hard drives and video camera connections. While many people did not use this feature, it was a great thing for power users.

MacBook Pro 

The MacBook Pro features many of the same updates as the MacBook, including the glass trackpad and the new styling. In addition, the MacBook Pro adds more pro-level features

Dual Video Cards 
In the MacBook, there is an integrated graphics chip on the main board.  The MacBook Pro has this same chip on the board, however, it also has an independent graphics board that can be switched between depending on the need for longer battery life or more graphics power. 

Other Updates

The MacBook Air got a speed bump along with the new graphics chip that was added to the MacBook and MacBook Pro.  A new LED backlit 24″ cinema display with a built in magsafe connector and DisplayPort input was also announced.  This new display is only compatible with the newly released laptops with a mini DisplayPort connector.