Share 'What is "Dieselpunk" to you?'

The subject keeps coming up as to what "Dieselpunk" means, be it a genre, a subculture, an aestetic, a lifestyle, etc.... This keeps getting discussed in every other topic to the point of derailing discussions, for which I admit my own guilt as much as anyone.  it seems worth having a topic just to discuss this centrally important issue.  As Larry mentioned in another thread, this is a big tent w…