Thanks for all the replies.
Valence- I can appreciate what you're saying. The wires may or may not be the final versions depicted here. I may do some more detailed work on them, but I don't think I'll be removing them. I particularly like how the wires connect the buttons and form an "inner shape" to the panel. The two going from the joysticks to the edge of the panel are to add help break up the black space, and I may play around with them.
Niko, yeah, I've been somewhat concerned with the weight issue with the mame logo. I like symmetry, and without more buttons for the panel I thought the logo would the answer. I like your idea about enclosing it in a box like the Mame buttons, which I think I'll do. About expanding the concept, I realized it would be pretty cool to take the empty space on the marquee and put a processor there with wires that radiate out of it, to complete the theme... so I guess I'm not 99% done

And no, I'm not adding trackball buttons. I'm actually hacking a xarcade controller along with 3 mouse buttons to get the final layout. When I'm done I'll create a custom controller file for Mame. The layout should work well for selecting games and if I need to do serious windows work, I'll use the mouse on the monitor shelf.