At ISO 50 it's not likely that you are going to need to worry at all about noise, which is clear in this photograph of yours. Your long exposure turned out very nice indeed.
I think that the color is a bit off, though. If that were my photograph, I'd increase the brightness a touch, keep the saturation about the same, and take out a touch of the yellow...hmm, or is it the green? Well, I'd play around a bit more. Was this on auto WB?
No matter what, it would be a keeper for sure in my portfolio. It's a moody photo that makes me want to be there. I'd follow the lights and walk up the street a bit to see if something interesting was going on. Those two little lights in the forground building make my imagination swell...what they heck is goin' on there at this time of night?
I took it upon myself -- I hope you don't mind -- to try to enhance the mood of that photo, so I played with the colors a bit, did some layer stuff, and ran it through Neat Image. This is what I came up with: http://www.brrd.ab.ca/nnorway/carrwe...y_filtered.jpg
I hope you don't mind, and please don't sue me for toying with your wonderful photo.
PS - a few of my "moody" people photos taken this festive season. I welcome any comments and thank you for kindly posting that great photo you shot.