Nice! A lot better than I could do in Paint.NET. I use Photoshop, Illustrator, and GIMPshop to do my images.
Another good one that can make abstract art is "Digital Dream Studio V2," which is freeware, available from freewarehome.com, and it MIGHT be open source. I've been looking for the source to it for a while so I can change some features so that they're easier to use.
Overall - NICE!