GroovyMAME and MEWUI have > stopped, but that's because all of their features are part of MAME itself so those > users can come home.
From what I've read here - http://forum.arcadecontrols.com/index.php/topic,135823.650.html groovymame code it's not ready for next release and probably will stay as patch for some time. There is also problem with highscore support (much loved not only by CRT users) not too mention no nag patch which of course will not be putted on mame.