As most of you probably already know tomorrow is the day that the much awaited iPhone 3G launches worldwide, and as with the previous iteration of the device Apple is looking to produce a media splash ahead of Friday by sending out review samples to the usual mainstream reviewers: Walt Mossberg from the WSJ, Ed Baig from USA Today and David Pogue from the NY Times.

The three of them have weighed in on the device and found it to be an improvement on its predecessor, though hardware-wise everything is pretty much the same with the obvious exception of 3G and GPS. The audio quality during calls and media playback is also greatly improved due to an enhanced speaker, but many standard smartphone features such as voice dialing, copy-and-paste, Bluetooth stereo audio, and MMS are still missing.

The real big deal here is the App Store, which will presumably help the iPhone handle any function that Apple's own software can’t.

Among the shortcomings mentioned in the reviews are the weaker battery life due to 3G usage, more expensive service contracts, and the phone’s rather limited GPS antenna which is too small to replicate the turn-by-turn navigation of a standalone GPS unit.