What I like about this picture, other than the fireworks and colors, is the symmetry. The fireworks, the streetlights and the tree to the right complement each other, the lines are parallel.
Not that much post-processing. Processed the raw file with Dxo Optics Pro 4.1, cropped and tweaked with CS2, selective sharpening and frame.
Took this picture on new years eve. Since I submitted it to a photo contest I didn't put on flickr right away.
Some have commented on the first streetlight, I actually like it. If you let your eye wander towards it and follow the streetlights, they lead you to the base of the fireworks.