Alpha Centauri is, of course, one of the first systems that come to mind. I believe that it wouldn't be that hard. Alpha Centauri, being really close, has the advantage in that both of it's stars have a rather large seperation. Proxima is really seperated. If this method is used on Alpha Centauri B, we may be able to find any planets in a shorter time than the 5 years Greg posted on the Systemic blog. Likely, the intrinsic jitter of the star would be the only limiting factor.