This is unexpected, albeit we didn't know exactly what Apple has included (as there is no official changelog released) to their latest firmware software when it's released yesterday, but most of us were sure the company should have placed the patch for the untethered exploit, but we were wrong.
The firmware is still defenseless against any exploits, therefore we are quite sure to recommend you to update to the iOS 5.0.2 firmware. The news of this was brought by Kb @nitoTV.
Unfortunately it's not for ATV3, therefore to those who own Apple TV 2, you are safe to upgrade to the iOS 5.0.2 firmware. And have some fun with it. Cheers.
Update: Now you can download Seas0nPass to untethered jailbreak Apple TV 2 running on iOS 5.0.2 firmware.