You should know by now that Microsoft enhanced Windows XP anti piracy measures with Genuine Advantage v126.96.36.199 (KB905474). Just like all its predecessors, the new WGA too seem to have been cracked.
The release .nfo claims that the crack is "100% working on Windows Update, Microsoft Download Center and Microsoft Update". I've seen positive comments from people who ran it on XP SP2 and XP SP3 so it does indeed seem to work.
There is not much information available on the crack's creator/creators; creator is identified only as 'wind'. It doesn't look like a scene release as it has not been on any of the scene pre channels that we monitor. However, a line in the release .nfo file reads "A tribute to ETH0, creator of base version crack." so we can assume that this was based on the popular WGA cracks released by scene group ETH0. ETH0 quit the scene a while ago after they were accused of having insecure members in the group. Someone seems to have continued ETH0's work from where they left it :)
Anyway the pirates have beaten a MS copy protection yet again. Now how many times have we seen that happen?