Here are a few stats for anyone who's interested...
I submitted the first version of my app Tuesday, July 21st. Apple reviewed it Monday, July 27th. I received a rejection notice on Thursday, July 30th. (More on that in a minute.)
I resubmitted the app on Thursday, July 30th. Apple reviewed it Thursday, August 6th. I received an approval notice on Friday, August 7th.
My app is called iGarageSale and it allows you to browse and search garage sales from craigslist. I had originally rated the app as 12+ when I submitted to Apple since it pulls in sales from craigslist and I have no control over the content. I figured citing the app as having infrequent mature content was sufficient since it is really only designed to view garage sale listings. Apple determined that by allowing unfiltered access to craigslist, a 17+ rating was required. If you're interested in more details on all of that, I've posted a blog post here:
http://www.igaragesaleapp.com/blog/17-up-rating-explained/
Aaron