We recently had a question about response times to unagented manuscripts. For those who don't know me, my name is Rene Sears, and I'm Editorial Director Lou Anders' assistant/ slush reader. Pyr began accepting unagented manuscripts last February, when I was hired. Unsolicited manuscripts are called slush; my job is to read them and pass the exceptional ones along to Lou, who then decides whether they are right for Pyr.
To answer the original question, my aspiration is to keep rejections within four to six weeks; sometimes it may be longer. If I read the first few chapter and like them, it may take me longer to get a chance to read further and see if the manuscript lives up to its initial promise. At the moment, my response times are a bit slower than usual, because I'm also helping prepare our backlist for ebook conversion. If you are worried your manuscript has gone astray, you are welcome to email me.
Any other questions about the slush pile, feel free to ask in the comments.