From what I have observed with a good content and quality back links past 2yrs old domains can rank as good as or better then very old domains , hence domain age in my opinion is a temporary factor for very young websites up to 1.5-2 yrs the most .
From what I have read, the 1 year mark is when most websites close. Something like 85%- 95% of all sites will close before they are 12 months old. This is especially true for forums. That might be why google does not rank young sites very well. Why give the site a good rank if its just going to go off line in a few months. But once a site reaches 18 month - 24 months, that is when traffic and ranking will start picking up. But once again, most people want instant success and are not willing to wait that long.
To me it looks like a well optimized new domain is loosing something like 10-30%(as we can only guess) of its SERP power till it reaches a certain age, but I am more then positive that the age is no more then 2 yrs . I guess the age does not affect SERP after the threshold is passed .
Domain age can really help a site but as Brill stated its only one factor. The age of the links pointing at the site is a factor helping these old sites.
All the time, content is the KING. Even, u don't have much backlinks u can get in to SERP with good on-page optimization following keyword density, rich featured content, seo friendly Title, Description. Domain, age is having less importance now a days... but, when coming to the high competition keywords it is important
I'm sure that Age is important but it's probly not just the age of the domain. If I have a 10year old domain then it means I probly have a lot of aged links.
Domain Age is doest not play any main role in SEO. It just simple factor. If your site having good content and valid backlink then your site will get Good PR and SERP.
Pr and ege has like no conexion As for rankings age is one of those many many small factors like 200 that "help"
I find my sites are out of the sandbox at around the 8 month point and reaching their full potential after a year.
I don't think now days it works, you have to keep your website updated or build links. Otherwise your rank and traffic goes down very quickly. Check out this post It may be helpful http://forums.digitalpoint.com/showthread.php?t=1372992
The content is the most important thing. If you have a website with 10 years age without SEO onpage, you cannot beat a 1 month website with SEO on-page and well indexed by Google.