According to a number of posts over on the MDL forums, the server that was allowing activations of all the leaked RTM images has now been either taken offline or blocked for new requests.
Information has since come to light that the server was located in Russia, and allowed hundreds of activations before being taken offline. It's unclear what action was taken, either by Microsoft or the owner of the Key Management Server (KMS); but judging from the posts over on MDL, it seems that anyone trying to activate Windows 8 illegally on that server will be disappointed.
To recap, yesterday messages started appearing on Twitter that it was possible to activate all four of the leaked Windows 8 images that were leaked over the weekend, including the earlier leaked Enterprise "N" version by pointing the activation sequence to a server located in Russia.
It probably won't be the last we hear of leaks and bypasses, but for now it appears it's a win for Microsoft.
Windows 8 will be made available on August 15th for MSDN and TechNet subscribers, and on October 26th for retail purchase. Although pricing has yet to be confirmed, a rumor suggests that Windows 8 Pro could be made available for around $70 dollars, or at the confirmed $39,95 upgrade time-limited offer.