Just got the final edits on By Chance this evening. My publisher's added an extra step to their editing process: now, after line-edits, we get a "source file" that we have to go over in meticulous detail, sort of like galley proofs.
After three previous editing passes, I'm pretty sure my editor and I have weeded out most of the errors, so there shouldn't be too much, if anything, left to fix. I just hope I don't miss stuff because I've read the %$#@! thing so many times, I've gone page-blind. ;)