Work is now proceeding on MEPIS 8.5, which will use KDE 4.3. An alpha is expected within a few weeks, and then community testing will begin. You can keep track of developments by monitoring Warren's tweets and announcements on the MEPIS website (the RSS feed is helpful for doing that) and by checking on MepisLovers forum .
For unofficial community remastered versions, check this site and the MepisLovers forum to see what is available.
