The cat may be out of the bag as a recent Macworld article points out that while Apple’s recently-released iPhone 3GS is capable of much faster download speeds than the previous generations, its upload speeds could stand to see some improvement. While the handset boasts a 7.2 Mbps HSDPA downstream, which is twice the iPhone 3G’s 3.6 Mbps HSDPA speed, it was assumed that Apple would also be increasing upstream speeds by finally adding HSUPA, bringing upload speeds to either 1.4 or 1.9 Mbps.

A recent RapidRepair teardown revealed this not to be the case. When the group cracked open their iPhone 3GS, they found that it still only had a UMTS/HSDPA chip. While it had increased HSDPA speeds, it only supported UMTS, the earliest 3G upload protocol in the U.S., which is only capable of peak speeds of 384 Kbps.

While download speeds with the 3GS are quite a bit faster (or will be in the U.S. when AT&T finishes their 7.2 network), upload speeds remain comparatively slow.