For those of you that are concerned about upgrading your baseband, we have good news for you. The popular custom IPSW tool Sn0wbreeze has received an update that brings support for iOS 6 and 6.0.1. As opposed to redsn0w, which loads a payload on to your device to jailbreak it, Sn0wbreeze is a tool that actually constructs a jailbroken IPSW which you can then use to restore your device. The changes are as follows:
What is New?
Added 6.0 (10A403)/6.0.1 (10A523) support. (Only includes iPhone 3GS & A4 devices).
The 6.0/6.0.1 is currently a tethered based jailbreak via iBooty (except for iPhone 3GS old bootrom users).
SAM is built-in for iOS 6 hacktivations. (Hacktivated phones can reboot to a semi-tethered state after being activated [rather than just hang at the Apple Logo]). Kudos @sbingner!