You may be interested in the files here:
http://www.behindthename.com/top/analysis/
They aren't formatted for public use, so they're a bit difficult to understand. They show how the top 1000 names of the year compare to the names of last year. The first section shows the net movement of names of various usages (eg English names, French names, etc). The second section looks at name length, and the third looks at the initial letter of the name. Of course names generally do not rise and fall based on their length or initial, but at the time I wrote the code I was interested in seeing if there were any long-term trends.