On January 28th, a mere five days from now, iOS 6.1 beta 4 will expire. If the past is any indication, then Apple will act, either releasing a 5th beta for iOS 6.1, or releasing the iOS 6.1 golden master — a final baked version, which shortly precedes a public release.
Since the firmware expires on the 28th, then I don't see Apple waiting until that day before making a move. The most realistic time period for it to drop a new release — whether it be beta 5 or the golden master — would be tomorrow, the 24th, or Friday, the 25th.
The big question is whether or not Apple decides to push out another beta release, or feels comfortable releasing the golden master (final) version of iOS 6.1. While it's not unheard of for Apple to go more than four releases deep into a beta period — iOS 5, for instance, saw seven different beta releases — it would be only the second time that this has happened for a non-major release.
The reason why the timing is so interesting for us, is because we believe that the hackers working on the iOS 6 jailbreak are waiting for a final version iOS 6.1 to be released, before finishing up and releasing the long awaited jailbreak. How do we know this? They basically told us as much...