There’s a Web site that reports how long science-fiction authors have had to wait for responses from various publishers. It’s called “Submitting to the Black Hole“.
Some people had to wait more than a year just to get a response. And some are still waiting.
Then again, some got a response in a matter of weeks, or even days (though the averages aren’t usually quite that good). So if/when I’m ready to submit something new for publication, I think I’ll be spending some quality time with this list.