I'm definitely interested in a way to track user histories, and I am sure the log files will be helpful to build such a thing. As it stands, we can do Unix diffs, the equivalent of Git change logs, on the text files. But this is not available to regular users directly, and as michih points out, changes in the logs occur not only for your new travels but as highway data is updated and expanded.
Here's what I'm most interested in at the moment. Some of the bigshots around here like to tell us they drove another million miles of new road last year. I'd like to be able to check my own stats to see how much I added to my inventory, too. I'll never be in oscar's or mapcat's league, but it's still interesting information, at least to me. I can see how I can do it in several steps, but, since I know how to use git and GitHub, it would be easier just to bring up the appropriate commits without cross-referencing, or even do a git diff. But this means I wouldn't be interested in changes to my stats as a result of changes to the underlying databases, and at least in the US those changes would likely have only a tiny affect on my stats, since the database is pretty much complete.