For a baseline, let's first look at the summer of 2014 to get an idea of the ebb and flow of players logging in over the summer with its related holidays and good weather (at least in the Northern Hemisphere).
So we can see the PCUs dip as June and July unfold and typically pick back up in the end of August.
Now, let's see how 2015 is doing:
So far we see the traditional dip starting in June but July has been trending higher than we saw in 2014. Not gob-smacking outrageous improvement, possibly not even a statistically significant improvement, but the low point of the summer so far was prior to Fozzie Sov's deployment on July 14th, not post.
There's not enough there to say that Fozzie Sov is a success in its current form, but I am happy to report its not a failure either. And I recognize that the July 14th deployment was one more milestone on the imfamous three year plan of CCP Seagull, so the stage is set for the next big part.
Charts courtesy of EVE-Offline