Iphone 4S Price Drop or Iphone 5?

Alright so since the Iphone 5 is going to be released on September 21st than the prices for the 4S 32/64gb are going to drop, right?

Also I've never had an Iphone before should I go with the 5 or 4S?

Is it really that great?

What makes it soooo much better than the 4S?

thanks in advance