The iPad already has wifi............ If you have 3G it will still have wifi if you are in one place.
There already has been! The iPad 2 & 3!
Already been built. The iPad 3 went on sale March 2011. The iPad 4 went on sale November 2012.
Mainly from the App Store pre-installed on your iPad!
It is already out
No, the IPad Air is thinner and lighter than the iPad 4
The iPad mini and the iPad 4.
If you already have the iPad, given our time with the new iteration, we suggest giving the iPad 2 a miss. Sure it's faster, but that's speed you may or may not really need (given how fast the original iPad already is anyhow).
It already came out!
There is no iPad 4 yet. The current version is generation 3, or New iPad.
There is no reason to get an iPad if you already have an iPod Touch, especially if you are 13 years old.
There were a couple of major improvements from the iPad 3 to the iPad 4. The biggest was the improved performance of the FaceTime camera. Additionally, the iPad 4 retina display and speed were marked improvements.