Quick observation.. My site which is 2 years 5 months old to be exact is ranking in the top 10 for a keyword in which the sites on the first page have a domain age average of 10+ years old. One site was created in 1995, damn! BTW I only started SEO on the site in September 2010. Domain age does make a difference, but a smart SEO strategy will conquer all over time. Have a good one!