Yes. I have a complete ScummVM set on my cabinet. No keyboard necessary.. A trackball is a must though, obviously.
I also needed to map the F5 and F1 keys to Shazzam!/shift buttons on my Keywiz in order to properly exit and save my ScummVM games.
I think it's a terrific addition to my cab.. but, I suggest you have a comfortable stool/chair!

I got it to work by creating .LNKs which Mamewah ran. These links were directed to .BATch files which then launched ScummVM and the appropriate game.
The only tricky part... was that you HAVE to setup each game you want to add to your cab within the ScummVM menu before it'll allow you to launch that game from a batch file.
If you need my .ini and a sample .bat file, I can upload them. But, it's not that tough to figure out.
d.