We're very close from the day when iOS 5.1.1 untethered jailbreak is finally released. It is possible that the release will take place this weekend. Earlier today iOS hacker Pod2g revealed that if unlocking iOS 5.1.1 on your iPhone isn't that big a deal for you, then you should upgrade right now. More details after the jump.
Nevertheless if you're one of those iPhone owners who don't rely on a software unlock, then there's no harm in upgrading your firmware, since baseband upgrade is not an issue. Keep in mind that baseband upgrade in no way hinders your possibility of jailbreaking iPhone on iOS 5.1.1.
So a simple heads up for those iPhone owners waiting for iOS 5.1.1 untethered jailbreak on devices that don't need a software unlock. You have the green signal from Pod2g himself to upgrade right now to latest iOS firmware.
Update: Now you can make iPhone official factory unlock, you can check the details from here