HCM will see an update in the near future. Last I heard it was to be called 2010 edition and published accordingly.
MUTCD has gone thru a major revision and a 2009 version is now available
online. It was relased less than 2 weeks back.
As far as the PE exam is concerned, I don't see them adopting any of these changes anytime soon. So you and all the other test takers should be fine. Of course, if there are supplements to the HCM 2000 and MUTCD 2003 then those are certainly applicable.