Simple answer to the original question: Vinyl will be pressed as long as there's market for it. So long as people are willing to pay for it, someone will manufacture and sell it.
Vinyl's got something going for it that no other format can truly compete with - collectibility. Not everyone who buys vinyl has a turntable. Hot Topic had a bunch of vinyl, and still has some. Shooting the breeze with a few employees at different stores, they told me about half of the people buying vinyl actually played it. I actually thought the number would be lower, as Hot Topic isn't exactly an audiophile store.
I know a few people who buy vinyl just to collect it. They don't have turntables, but they buy stuff from their favorite bands and keep it sealed up. A lot of bands issue a limited edition vinyl version of their stuff, old and new. They'll do picture discs, colored vinyl, and so on.
Vinyl's got a swagger/mojo to it that downloaded music, CDs, and cassettes just don't have.
A lot of non-audiophiles are listening to it too. I think they're the younger people who don't buy very many CDs and are used to listening to pirated mp3s through crap headphones or sound docks. They probably buy their favorite stuff on vinyl (new and/or used) and play it on a vintage deck with old receivers and speakers. Likely their parents' gear from the basement or yard sale stuff.
Everyone likes what they like. It's just stupid to think that what you like is inherently more enjoyable to everyone, and they're dumb for liking something else.
I don't think the vinyl wave/fad/boom/whatever you want to call it is due to advertising, marketing, etc. I haven't seen a single ad anywhere, except places like Music Direct advertising their vinyl and gear in hifi rags.
As for me, I don't care why people buy vinyl. Doesn't change my life any, except for one good way - it keeps companies pressing vinyl. I love vinyl. I also love digital. It isn't really the format, it's the content.
If everyone enjoyed what they like and left people alone who enjoyed something else (so long as it's not Sandusky type stuff), it would be a far better world. Live and let live. I worry about my family and myself, not what the next guy's doing to pass his time.