I'm not sure that asking you about book progress qualifies as "polite" in writer etiquette...

Perfectly fine in this case, because: (1) I'm still beating my head against working on it; and (2) it's nice that someone beside myself is interested in knowing what happens next.

I do get a little testy when someone asks about a book that's stalled, or one that can't be written right now because of, y'know, that contracted books thing...