The right answer to that question depends on who you are. See if you can find which camp (if either) you fall into in our two lists below.
High-quality images are important to you. The foremost argument for the new iPad is its gorgeous, high-resolution display. It's sharper and brighter, and offers more compelling color and detail than the display on the iPad 2. If you appreciate the difference in image quality between standard-definition and high-definition content, you'll want a new iPad.
You love to play games. The new iPad blew its predecessor away on our PCWorld Labs graphics tests.
You need to use a fast connection everywhere. The new iPad is the first Apple tablet that can connect to 4G networks. (You can buy a new iPad that works on either AT&T's 4G network or Verizon's 4G network.) If you go with Verizon, you can also use the iPad as a hotspot, allowing other devices to piggyback on its wireless connection. And Apple now sells only the Wi-Fi version of the iPad 2, so if you need an anywhere connection, the new iPad is your only option among Apple tablets.