It's been three months now and I still haven't heard anything from Harlequin about my novel. Apparently, this isn't unusual. I've heard of responses taking up to a year.
I've been trying to decide whether or not to start approaching agents to see if one would be interested in representing me. I don't want to step on any toes or breach any taboos but three months seems like a reasonable length of time to allow for an exclusive submission.
Consciously, I know that the road to publishing is difficult, particularly if you want traditional publishing. (With self-publishing, sales and quality control are the biggest challenges, as far as I know.) However, my little eternal optimist inside had visions of book covers and advance cheques dancing in her head. So it's a little sad to have to give her a reality check.