Domain age is a very powerful it not one of the most powerful factors affecting the ranking of your site. Domain age is the most powerful factor in "TrustRank" - an algorithm not openly admitted by Google. I've ranked for great keywords against people that use BlackHat SEO by taking into account factors such as Domain Age and TrustRank linking. Feel free to ask me any questions about how Domain Age and TrustRank are affecting you right now, I will answer in this thread. Also if you PM me I might not get it since my inbox likes to be stuffed.