Touch Sensitive Buttons -turn the Xbox 360 on or off and eject a disc with the swipe of a Finger
Whisper Quiet – Whether you’re playing a DVD disc or from the hard drive or navigating the dashboard, with the all-new and much quieter Xbox 360, the only noise you’ll hear is your own laughing, cheering and playing
Wi-Fi -Built-in 802.11n Wi-Fi for fast, easy connection to your friends and entertainment on Xbox LIVE.
Hard Drive - 250GB internal, swappable hard drive for even more storage. To access, remove the bottom panel by pushing the small tab toward the front of the console.
Kinect-ready -Custom Kinect port on the back of the console that directly hooks up to the Kinect sensor for controller-free fun.
USB Slots - Five USB ports, three in the back and two in the front.
Power Supply -Smaller and more efficient. Xbox 360 250GB and Xbox 360 Original power supplies are not interchangeable.
Wireless Controller -The award-winning Xbox 360 Wireless Controller matches the console in all black with color-matched thumbsticks and directional pad with a touch of gloss and chrome to complete the look.
Backward Compatible -Your favorite accessories and games will work with Xbox 360 250GB. Xbox 360 external hard drives and Memory Units are not compatible.

Although all accessories and games will work with the new Xbox, the existing HDD will not… so how will i get all my stuff over to the new Xbox after I buy it? Good question and I do not know the answer at this moment. Check out this site for some pics.