RUMPLESTILTSKIN  This is a very interesting application. Seems to be quite happy playing with MPEG4/H264 (avc1) files. Does picture-in-picture in a snap. Titling is also quite easy and intuitive. It's almost like the offspring of FCE & iMovieHD (and I mean that as a compliment). I'll definitely be working with this app to see if it will be the right workflow for my NLE needs.

I'm not providing a rating of any sort yet as I don't know the app well enough to provide a valid judgement.  
(Version 3.0.6)

BACKPACKER  Revision 4 of MediaEdit 3.0.1 (released April 8 '08) has fixed the crashing in the Audio function when USB-headphones were or were not used, or plugging and unplugging them.

Thanks for being on the ball!  
(Version 3.0.1r3)

BACKPACKER  Revision 3 of MediaEdit 3.0.1, released April 7 '08, finally works on my G4 with Leopard. Thanks.

BTW, as with v3.0.0, selecting Audio (on the right-hand-side of the Project window) consistently causes crashing if my USB-headphones aren't plugged in. It seems like M.E. remembers that I first tried it with the headphones, and now requires them for the Audio function always. Unplugging the headphones in Audio also causes the crash ('An exception of class NilObjectException was not handled. The application must shut down.')  
(Version 3.0.1)