Looking back on the 2012 cycle, through the summer months Obama only maintained a 4, and at times 3 point lead over Romney. You can see below from the polling average chart from Real Clear Politics that Romney and Obama spent most of the summer in 2012 about 4.5 percentage points apart, but at times were a lot closer. At one point nearly being tied in the early days of the summer.
The largest spread came some time in August around the time Romney was being dogged over his taxes. Prior to that the race remained in a band between Obama with a high end of 48.5% and 45.5% on the low end Conversely, Romney topped out at 45.5% and hitting a low end (with his tax controversy) at about 43%. Romney and Obama even at Romney's worst point and Obama's best point were only about 5.5% apart in the polling average. Clinton at times has held leads as high as 7% in the average.
While this polls could be showing the reversal of the past week and be on the leading edge of a post convention/ pre debate slowdown I don't think there is much here to see. Even if the polls do fall back in line with what Reuters is showing here, it would still only be consistent with past elections late summer days.