One of the issues that I have with the images is that the sky is getting too dark. I wanted a little more of the Dusk look, which is what I was looking at, but it didn't come across in the image. Noise was a big issue that I had to deal with, I am shooting on a Canon 30D, and even at ISO 100 and trying the long exposure noise reduction, the sky was terrible!! I ended up duplicating the layer in photoshop, using the median filter to remove all noise, and then with masking just the sky, lay it back over the original at about 70% opacity so it brought back a little texture. I'm hoping that if I catch it a little earlier, there will be enough light in the sky to get some nice rich color, but not too early so that the lights aren't visible.
The moon was rising during the shot as well, but with needing the wide angle, it didn't fit well with the photo so I removed it.