You might get a better answer in the MSDN Forums, but from the similarity with HKEY_CURRENT_USER, one would think that it would represent a registry hive for non roaming settings for a roaming user profile.
It does not appear to be used yet, at least not in build 7000. I don't find it in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\hivelist.
Marked as answer byNick FVTuesday, May 26, 2009 1:56 AM
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