I'd guess the currently, 95% of people with dslr's do not know much nor care that much about photography. Since about a year or so ago, at least around LA, I'd say half to more people at touristy places are walking around with a dslr. Most of those are walking around with an entry level dslr with a kit lens or two. A smaller portion buys more expensive body and lens but still don't know much about metering, shutter speed rules, composition, etc. They just put it in P mode and figure IS gives them better image b/c it costs more. Then the smallest portion of folks actually know a lot about photography.
I suspect a significant amount of folks are using dslr's now days b/c digicam have serious limits like slow and poor AF performance, long shutter lag, long delay between shots, small buffers, poor indoor (high ISO) performance, poor ergonomics, and lack of real wide angles. The availability of dslr's for under $500 or so have been really good for folks.
Just b/c one has a dslr doesn't mean that they have to be a serious photographer. I say good for those folks who want a nice camera. Digital technology has really brought a renaissance to photography and I'm happy to see folks getting out and taking pics.