I always try to design logos so that they work in black and white, period. No grey, no gradients, just black and white. Once you get that established, then start adding color. Your concept is good, it just needs balance and some management of negative space.
Also, Arial?
I know I'm being a snob here, but seeing logos made with fonts that ship with Windows upsets me. There are a million sans-serif fonts out there, and most of them are better than Arial. Avenir, Avante Garde, Century Gothic, Gotham, Folio, Interstate, Helvetica, Franklin Effing Gothic.
Check those out. You might be pleasantly surprised.