A lot of good advice...
This year I bought a Specialized Allez Pro 27 with a Dura-Ace triple...no kidding, Dura-Ace Triple. It's a 52-39-30 and I rarely ride the triple BUT it has come in handy a few times.
If it were me, I would buy the Roubaix now but that is only because I wouldn't be able to wait.