Get it here:
http://scummvm.sourceforge.net/downloads.php
This version won't work with the front-ends (at least, not to my knowledge).
This version has an in-engine GUI that makes launching games much easier...just browse for the folder in which the data file is in and add it to the list.
For Mac data files such as Day of the Tentacle, Full Throttle and Sam & Max, you'll need 'rescumm' to extract the data from it into a readable format for ScummVM.
Nice new icon.
If you need 2xSaI, full screen and other such things, you'll have to launch 'scummvm' from the ScummVM package. Simply context-click on the ScummVM app, 'Show Package Contents'...Contents/MacOS...open Terminal...drag and drop 'scummvm' from Contents/MacOS into the Terminal window and add (without the quotes):
'-g2xsai' for 2xSaI smoothing
'-f' for fullscreen
etc...
All the switches are mentionned in the Read Me file.
So far Monkey Island 1 still work well (without sound though

)
Monkey Island 2 works well (with low quality sound though

)
Indy works (low quality sound)
Day of the Tentacle works great!
Full Throttle works (but some problems with sound fx, music and speech)