AT&T's listing a new iPhone model, called the iPhone Black, on its account management site. Could this be the upcoming 3G iPhone we're all expecting Apple to release within the next couple of months? After all, the finish of the rear of that eagerly-awaited smartphone is a glossy black, as rumored leaks and pictures have revealed over the last few weeks.

Whatever the significance of the listing, it can be seen as yet another indication that the days of the creepy crawly EDGE-enabled iPhone will soon come to an end.

Update: According to an AT&T executive who spoke with Gizmodo, the iPhone Black in just a temporary placeholder for a "scheduled catalog update" for a current iPhone model, not for the coming 3G edition. That sounds a little fishy to us.

Meanwhile, Telecom Italia Mobile executive VP Luigi Licciardi's just asserted in an interview that "we will sell the iPhone 3G next month." The very same month of Apple's Worldwide Developer's Conference (WWDC), this will take place from June 9th to 13th in San Francisco.

Hmmm. Now that's even less discrete than AT&T presumably's been with the iPhone Black reference. Apple can't be happy about that.

Rumor has it AT&T will subsidize the cost of buying the new and improved iPhone considerably when it ships. Sign on the dotted line for two years of service and you'll be able to get an 8GB 3G iPhone for only $200 and a 16GB edition for $300.

The new iPhone should integrate GPS to better support location-based services than today's iPhone's cell-phone-tower triangulation method. And, in spite of the addition of 3G and GPS, the new iPhone models will be a little thinner than the original, dropping to only 9.2mm thick from 11.7mm.

In June, Apple will release iPhone software update 2.0, which, in all likelihood will be included in the next-gen iPhone. This upgrade will feature the iPhone App Store, where users will finally be able to wirelessly download official native software directly to their iPhone, over a Wi-Fi or cellular connection. You'll also be able to side-load programs through iTunes.

The new iPhone firmware, which will cost iPod touch users a nominal fee, will also introduce a host of additional new features, including a number to make the iPhone more enterprise friendly; such as the integration of Microsoft ActiveSync technology to support push e-mail calendaring, and contacts, as well as global address lists and remote wipe in an enterprise environment.