Well it looks like iOS 4.3 Beta 2 has more stuff secretly hiding deep inside the firmware. An Italian blog iPhoneItalia has now uncovered thumbnails for crop and rotate functionality which indicates the arrival of this feature for basic image editing natively in future iOS versions.
Whether this functionality will be available come the final Gold version of iOS 4.3 is yet to be seen, but what we know now is that Apple is testing this functionality and we might have it fully implemented in the upcoming iOS firmware updates.
UPDATE 1: Looks like it has been there since firmware 3.x days. Thanks Mark Gurman !