I suppose so. Usually if your alignment is off you'll notice the car pulling to one side or the other if you let go of the wheel on a perfectly flat road (heh, find me one of those around here

)
I recently had my alignment done, and after 4 years and 55000 miles, my left front was off by a little bit, but nothing major. And that's after two minor accidents and clipping a curb in the snow. If you get it checked out, make sure you take it somewhere where they won't rape you (or charge you at all) just to have it checked. If its really bad, then get it done. Even if it isn't the cause of the vibration you can reduce tire wear if the alignment is way off.