it says that I need an update if I'm running anything less than 1.27.502.12 but it appears that I cannot get the update from HTC since I'm using a mac and not a PC. I'm just curious if anyone knows if AT&T is pushing this out yet or what I can/should do.
Updates rollout sequentially to customers (in some order apparently known only to AT&T), so you just need to wait your turn. The system simply doesn't have the capacity to update everyone at the same time. Might take days or even weeks.
HTC Sync doesn't require the phone to be SIM unlocked. Where are you getting that info?