Movies coming from books is no new thing. It's been going on forever, and the recent trend in YA movies is merely a continuation of a trend that's been going on for a very long time. I guess what makes it "new" is the fact that YA lit being a big thing is a relatively new occurrence. Back in my day, the line between YA, MG and adult lit was much less defined. Series I grew up with like the animorphs, which would likely be labeled YA if they came out now, where shelved with MG and indeed elementary school is when I started picking them up.
As far as I recall, they really didn't have a "YA" section at bookstores when I was growing up...it was either lumped in with the MG or adult lit, depending on how "mature" it was....and this was not too long ago, either. I'm talking about the 90s-very early 2000s, here. Seeing that, I think the "trend" towards YA movies is really just a continuation of the long-standing tradition to turn good books into movies....it's just that YA is now finally getting respect and definition as a genera and as a result your seeing more YA books getting turned into movies alongside movies inspired by non-YA books.
As for my own work, quite frankly I'd not want to see any of it turned into a movie unless it was an animated film with anime style art(or at least CG that looked vaguely anime-esc alla many JRPGs like Final Fantasy). Reason being I can't imagine my characters ever looking like normal, realistic people with their crazy-styled, technicolor "anime hair" and outrageous science-fantasy outfits. Of course, if I ever did get anything published, chances are if by some miracle somebody wanted to make it into a movie that film would pretty much have to be an animated feature as the budget for the CG that would be needed to render my settings and over the top magical powers would be too pricey for a film based on the work of a debut/relatively unknown author.
