Have you tried inverting this photo? I had been trying to capture a good smoke shot for awhile, and then figured out that if you inverted a picture just like this, it really enhanced the beauty of the smoke! I entered my shot in the New Year's Resolution challenge check it out here. Your shutter speed is much faster then mine, so I wouldn't worry about that! A nice smoke shot for sure, just need a little kick, or something to give it some grab!
This needs either a crisper focus or a shorter shutter speed because it seems that one or the other is giving it a blurred appearance. If you could get this come come out sharp as a tack it would be a pretty cool shot.