In the comments section to a post below, writer Patti Abbott writes:
I've been reading Second Hand by Micahel Zadoorian, a book written around 2000 and set in Detroit. I wonder if a case can be make that novels written pre-9/11 have a completely different feel to them. This is leisurely and the angst in it manageable rather than apocalyptic. Do you see a difference?
I've been thinking about it, and I can't say that I've seen any major differences between the books I've read that were written before and after 9/11. Obviously there are some subject matter differences (in some books, at least), but in terms of themes, style, etc., I can't point to anything.
I think the differences between individual authors and books are so great that it's difficult to generalize much in terms of how books overall might have changed. I'm sure that some authors have changed, or some books have changed, but I haven't seen any widespread differences in the genre as a whole.
It's an interesting subject to think about, though.