Official Unlocked iPhone 4 in US this Wednesday?

Apple could begin selling unlocked iPhone 4 handsets in the US as early as this Wednesday, according to the latest leaks. Arch iOS insider Chronic scored what are believed to be the part numbers for the new unlocked iPhone 4 SKUs headed to Apple Stores midway through this week, including both black and white versions of the fourth-gen GSM smartphone.

According to his source, four units will be available: the MC603 (16GB, Black), MC604 (16GB, White), MC605 (32GB, Black) and MC606 (32GB, White). No word on pricing at this stage, though any unsubsidized device is obviously going to be considerably more than the $199 entry-level iPhone 4 AT&T currently offers in return for two-years of contract commitment.

Although Apple offers unlocked iPhones in other countries, until now AT&T has had an exclusive on the smartphone in the US and owners have been forced to turn to unofficial unlocking methods if they want to use a different carrier's SIM. However, even if the rumor pans out, the quadband iPhone 4 would still not play nicely with T-Mobile USA's 3G network, leaving customers of the carrier stuck on EDGE data speeds (or WiFi, of course) at most.

Instead, this is likely of more interest to those who frequently travel internationally with their iPhone 4, and would like to be able to slot in a local carrier's microSIM and take advantage of local rates rather than pay AT&T's roaming fees. There's understandably no mention of an "unlocked" CDMA iPhone 4, since the CDMA standard is less amenable to carrier swapping in the manner that the GSM standard permits.