I just purchased a 64 gig 4G this was an upgrade from my 16 gig 2G. The difference between the two units is astonishing. The retinal display is nothing short of the "holy cow" level of better. I now have full push notification and alarms. More on this later. Watching the TV shows and Movies I have converted to play on a Touch is a real treat. Some of the many, many gigabytes of Anime in my collection have subtitles I never could read them on the 2G, they are clear as can be with the 4G. Yes the cameras could be a little better but they work well enough. Would I wait, no, I would not and did not. As attached as I was to my Touch 2G, the 4G is fantastically better. I had the money in hand for an iPad. If you look at the functionality of the Touch 4G except for the larger screen the the 4G blows the the iPad out of the water. We will see the up grades the iPad "2G" will have this next Wednesday. It will not have the retinal display, it will have at least one camera for Facetime, it will be lighter and perhaps thinner. I will get an iPad eventually perhaps a iPad "3G" with a dual core processor and a retinal display only time will tell. Right now it is the Macbook Air that has my attention.
Now for the push notifications. I have an app that notifies me of earth quakes with the 2G I could check to see it there where any tremblers by opening up the App. With the 4G I get an on screen notification and a audio alert. I happened to be on Skype this last week end in what we call a round table in amateur radio. one of the people in this round table happened to be on the southern tip of the North Island of New Zealand. While we were taking a polite voice on my Touch said "excuse me there has been an earth quake" with that statement a window with the data opened up I saw that it was a 6.3 on the modified Richter scale and was closest to Christchurch, NZ at 3000 meters in depth. I passed this on to Russell in NZ. It was interesting there was nothing on his local radio station for almost a half an hour and Russ first learned of the earth quake from a person sitting half way around the world.