is this going to suffer from the same problems as increased class sizes? less personal mentoring, for example?
Probably NOT. The bar has been higher in recent batches and as a result, relatively more established companies make it to the batch, as compared to, say, in 2005 - 2007. This benefits both the companies and YC -- the companies benefit by the excellent environment and networking opportunities, and YC ends up making somewhat (again, relatively speaking) safer investments.
YC is certainly getting and accepting applications from more established companies now, but they're also still funding very, very early stage companies (i.e., two founders and an idea).
My cofounder and I were in the Summer 2010 batch and fit that description, and I know of founders in this summer's batch who do as well.
Probably NOT. The bar has been higher in recent batches and as a result, relatively more established companies make it to the batch, as compared to, say, in 2005 - 2007. This benefits both the companies and YC -- the companies benefit by the excellent environment and networking opportunities, and YC ends up making somewhat (again, relatively speaking) safer investments.