So I couldn't wait any longer and decided to install current (I've been struggling with BT a bit lately so the updates yesterday were the proverbial straw).
However, Running cryptsetup from the install disk (current as of May 2) gave an error about "Too many levels of symbolic links".
Inspecting /sbin/cryptsetup shows it to be a symbolic link to
, which is clearly wrong. I notice that cryptsetup was moved to a new location in the May 1 updates. Perhaps this introduced the problem?