I don't think outputting the version is overkill at all. It's much easier and simpler to deal with it this way. Probably the nanosecond business is very much overkill, that only matters for a smaller subset of problem domains.
Whether the version is overkill depends on the frequency of version changes. If you're doing careful corporate releases with staging and QA on a two-month basis, it's definitely overkill - if you're doing continuous deployment with several releases daily and different systems running different versions concurrently, it's probably valuable.
