He wasn't on board straight away but it's clear that the principal architect of the Marvel Cinematic Universe is Joss Whedon. Whilst the Nick Fury cameo chucked into Iron Man's post-credit sequence was something of a gamble, increasingly Marvel Studios has been built around the Avengers films that Whedon writes and directs, which dictate everything that happens in the solo movies building up and spinning out of them. Most audience's conception of the Marvel movie characters is how they're shown in the Avengers films, meaning all the directors and writers who work on those solo movies have to not only be aware of but in tune with Whedon's voice. Guardians Of The Galaxy worked so well because it was very much on Whedon's wavelength. Which is good news for Spider-Man if Goddard really has got the gig, since him and Joss Whedon go way back. Much of Goddard's early writing work was on Buffy The Vampire Slayer and Angel, shows Whedon created, and the pair collaborated on the script for The Cabin In The Woods. It's a practical reason, but a good working relationship with Whedon bodes well.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/
