Great update to an established platform
Raspberry Pi is a excellent micro-computer platform for a wide range of DIY projects. It's a great learning environment for kids and adults alike who want to learn electronics and programming.
Same form-factor as previous Raspberry Pi B+ versions; WiFi now native to the board; Upgraded CPU and memory
Older Wheezy images will not work on this; So you can't just pull the SD card off an older model and stick it into this one; This means that you will need to burn a new Jessie or Jessie Lite SD card and reinstall everything if you want to upgrade the hardware for an older project.