I think it's a combination of a few things.
Yes, I'm sure the camera has something to do with it. The D300s has the same sensor as my D90, but I can't deny that even though I have less than 200 shutter clicks through it so far, I'm taking notably better photos. I'm also sure that since I've been taking these photography classes, my work has improved technically as well. I have a much better understanding of the exposure triangle. And last, there was a lot more at play here than just "bounced off the ceiling". I'm getting better w/ lighting too.