However, until the official release came through this week, there was still debate over whether he was the man - and the right man - for the job.
There were several reasons to doubt his appointment. WPP execs dismissed the idea that Heekin was being lined up for the Grey role. And some senior WPP-ers were less than flattering about the man himself. Moreover, cynics reckoned that the Grey rumours were a Heekin-inspired defence mechanism, after he was given no major role in the recent top-level reshuffle at Havas.
In the event, Heekin has proved his critics wrong. The Grey job - with the security of the WPP family behind him - looks more attractive in many respects than the job he has left behind.
But Heekin still has much to prove, not least that his personal brand has not been tarnished by association with the accounting issues that still dog his old home, IPG.