If you go to http://jpegclub.org/ or http://www.ijg.org/ you will find that there has been a new release of libjpeg (after 10 years !). From what I've seen from Gentoo, there seems to be a fair bit of compatibility issues with it, so it might not be advisable to throw it late into F12. But early F13 would be a good place for this - you can already branch for F12...
This bug appears to have been reported against 'rawhide' during the Fedora 12 development cycle. Changing version to '12'. More information and reason for this action is here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
It's been decided that Fedora is going to start using the libjpeg-turbo code instead, so this is a WONTFIX.