@dan_t - I saw @withoutboats mention a similar idea. We can do that, but it has the same breakage as changing the default, as “cargo new foo” would no longer work (assuming I understand you correctly).
I personally kinda like that “cargo new something” isn’t all that much to type, so I’m kinda leaning towards keeping it around if we can.
In case anyone is curious, the current version of the patch introduces a new --lib and also prints out a status when it’s done so you can see what kind of project you created. I’m hoping that even if we don’t end up changing the default, this will help users discover the other project type(s).