As an older rider recently coming to Roubaix what matters to me is the more comfortable geometry, the future shock for a little less getting banged around, and running 30mm tires at the modern lower pressures for even less banging around. Put all three together and riding is a whole lot more fun for those old joints.
So the reasons I would say to upgrade your 2009 are the future shock and the ability to run larger tires. No need for the fanciest frame or components, but nice wheels and, especially, nice tires are well worth it. I am running the S-Works Turbo Rapidair 30mm tires.