THANK YOU for this thread! WoW! I just installed mameMCE on the MCE box, Woah! TOO slick! I now have over 1,400 games available on the TV! This is a VERY slick interface, and I just cant say enough about it! It is like a trip down memory lane going throuh all the games, and being able to play them again.
MAMEmce is pretty kewl, as it does not actually "insert itself" in MCE at all. It, when selected, shuts down MCE, and just brings up an interface that emulates the look and feel of MCE. When you exit it, it just fires MCE back up again.
Now, to get control of it in a better manner than my wireless keyboard

I am looking at getting a couple of wireless game controllers for the pc, similar to the PS2 controllers. Logitec makes a decent one for around $35. Next is to figgure out how to map the controls, to keys on the keyboard that MAME uses, -vs- the default "joystick" operations that other games natively look for. Any suggestions on this one?