I got these two (64Bit) as my last.
Update for Windows 8 Consumer Preview for x64-based Systems (KB2691252)Installation date: 11-04-2012 17:11
Update for Windows 8 Consumer Preview for x64-based Systems (KB2693205)Installation date: 11-04-2012 17:11
But, I am not certain, that may have been after a reinstall.
However, I can see on my history I have 16 in all, for the OS alone.