What is difference between 2g and 3g iTouch?

I ordered a 3rd Generation iTouch from Wal-mart. They sent me a 2nd Generation. What is actually the difference/benefit to a 3rd Generation iTouch. I assumed there is something better that I will be missing. Thanks!

http://www.everymac.com/systems/apple/consumer_electronics/ipod_faq/differences-between-ipod-touch-3g-and-ipod-touch-2g.html