A great start! Love the effects, especially the on the D. However, the arrow isn't cool. It reminds me of male reproductive organs or a Viagra commercial. Please do something different with the O. Thanks.
However, we're going to print this logo on envelopes and letter heads, so I think a white background would be best. The mirror effect probably wouldn't look good on paper, either.
One more thing: could you please remove the oval surrounding the logo?