I read an interesting article at IMnewswatch.com as follows: Please continue to read it and come back here to post your 2-cents for all of us to share/argue/debate/(butcher?)/etc.
This is all rubbish, Google does not put any site in supplemental index bcoz of it's domain age. And there are many other better and easy options to get any site out of supplemental results.
While site age does play a role in Google listings you DO have to have other factors as well. Check out some of the discussion related to it on other forums. Google has been updating their algorithms as usual, so to keep up on the game it's best to see what's going on. Unfortunately there's no true easy out for most things if you're looking to rank higher on Google right away, you'll have to take a number of different factors into consideration.