If you're thinking about the new iPad, ask yourself - do you need internet connectivity outside of WiFi? Cause otherwise ... pass on it.
There are three main advantages to the new iPad:
Faster cellular signal: I'm on a train for two hours round trip during my work commute, so the updated 4G signal is a godsend. It feels like I'm surfing on wifi, and it's helped me to spend less time waiting for things to load and more time reading, tweeting, and all of that good stuff.
Better screen: The screen has been updated, and it is unbelievable. However, the screens of the iPad 1 and 2 are pretty damned good. And pretty damned good is enough for the majority of people.
Upgraded memory: The extra memory is noticeable when using intense applications like games and streaming applications like NBA Courtside. Again, nothing dramatic unless you are really on the bleeding edge.
Does that get you excited? Are you someone that runs intensive applications and requires internet outside of wifi coverage? If so, then you've probably already upgraded.
If you're not excited, then please note that the iPad 2 is on sale new for $100 cheaper, and you can save even more money if you look used.