Well some of this info has been posted before as rumors but it does seem that they are in the testing phase of the 3G iphone. According to engadget it could ship as early as July. Here is a rundown of the confirmed new features.
PICTURE REMOVED BECAUSE PEOPLE CANT READ THAT THE PIC WAS FAKE
The first thing people will notice: the 2nd gen iPhone will be about the same size and shape as the first gen.
It will, of course, have 3G. And proper GPS!
The most noticeable physical difference is back of the phone is no longer metal -- the whole thing is glossy black, from top to bottom. The volume buttons are now chrome.
Because it's got a little less metal to deal with, it doesn't have quite as many angular edges. The battery is (still) not removable.
The phone itself will be slightly thicker than the first gen device.
The headphone jack will no longer be recessed, and will finally be flush with the body.
The device itself uses roughly the same size and resolution screen as the first generation product.
No solid word on battery life or storage capacity.
Hell Im happy with it being 3G but proper GPS, thats niiice. Obviously take this with a grain of salt since it did not come from Apple directly.
EDIT: YES EVERYONE I KNOW THE PIC IS FAKE AND YES ENDGADGET CONFIRMED TWO WEEKS AGO THE PIC WAS FAKE, BUT IT WAS THE ONLY PIC OF THE BACK OF AN IPHONE THAT IS BLACK HENCE WHY I POSTED IT