[yourpalkeith]

A variant of this idea that would be more useful to me personally would be some measure of how actively maintained my dependencies are. It would be nice to know if my long-lived project depends on something that has been abandoned.

Details might be tricky, given that some very useful packages simply don't need frequent updates.

[k__]

I like the drift metric more, because some libraries are simply stable and don't need much updates anymore, this doesn't mean they are bad for your system.