The ipad is great for what it is intended for. Surfing the web, minor typing, quick easy access to the web, watching movies or video from netflix or Hulu+, playing games. You are not going to be typing a term paper on it.
My wife uses it at work to check her email facebook and read books. The Ipad unfortunately has no connections other than the standard iPod, iPad port for charging and syncing.
Other tablets that are android based have USB ports and HDMI ports to show movies on your HDTV.
Apple refuses to support FLASH content. Which makes surfing the web not so much fun at times. Android tablets support flash.
There are TONS of educational Apps out for the iPad and Android tablets.
I like them and sooner or later I will end up with a tablet. I am waiting for Android to support changing Proxy settings. I work in a school and running around with a laptop is not fun many times. But toting around an tablet would be fine.
Also if you do something that you need to print on an ipad you better hope you can Email it to yourself or hope that your printer has an ipad app. I have an HP printer and they have a few apps for printing from the ipad.
As far as 3g I would not waste my money on getting an ipad with 3g and wifi. When you purchase the Ipad 3g it cost more and you HAVE to get a new line or new account with AT&T for the 3g unless you buy your ipad from a verizon store. Even then both AT&T and Verizon cap you at 2gb of data. If you go over that they either A: limit your speed or B: CHARGE you HUGE overage charges.
I'm not Sheldon! I'm the Flash! And now I'm going to the Grand Canyon to scream in frustration *takes two quick steps* I'm back