I followed those instructions to do the update. The only exception to the instructions was that 2008.05 already had SUNWipkg@0.5.11,5.11-0.86 but I went ahead and updated it to -0.94 via the gnome System|Administration|Package Manager before doing the steps below that.
One weird thing on boot though is that I now have:
OpenSolaris 2008.05 snv_86_rc3 X86
Solaris 2008.11 snv_94 X86
I booted into the last one... even though the 2nd one that shows as active with beadm list. Seems to be working OK, but I should figure out what exactly is supposed to be there.