Our primary focus is placing rent-to-own Tenant/Buyers in homes and 90% of them ultimately purchase the home. I think I read somewhere that a seller should realistically expect that between 10-20% of rent-to-owners actually end up purchasing (which basically says "don't count on it"), but when you do it right, it should be the exception, not the rule, that don't go one to purchase.
I also read somewhere that the rental rates would increase due to the displaced families from all the foreclosures. I don't think I've seen evidence of this whatsoever in my market. Families are consolidating and we've seen more folks try to negotiate heavily down on the asking price saying "I'm looking at 10 other properties just today" or "I have this other house where the owner will take this...can you match it". Rents are still strong in Baltimore, but I haven't seen an increase.