Although there can sometimes be such a huge void that the question is a 'no brainer', car rankings are notoriously difficult to define when one does not factor-in its driver's relative contribution. This is never straightforward because drivers are different: for instance, I think few would argue that the 2012 Ferrari is better than Massa is currently making it look. On the other hand, Alonso may be 'outperforming his car'. Ultimately, the McLaren may be slightly the better car at the moment; but it is impossible to say with certainty; and - if what I have just said is true - the margin is very, very small. What I feel much more certain about is that McLaren currently have the best driver line up of any F1 team.
If its average times Massa alone will add several years to the Ferrari lap time, I assume they have done something clever (maybe) to get those numbers more...real.