The Avengers and The Amazing Spider-Man represent the two biggest comic book movies of the year, but despite each coming from a different studio (Disney and Sony respectively), a crossover between the two properties very nearly became more than just outlandish fanboy rumour. Although the characters were never set to interact, Osborne Tower came close to popping up in the background of Avengers' Manhattan, functioning as both groovy Easter Egg and handy bit of promotion for the upcoming Spidey reboot.
Unfortunately, by the time Osborne Tower had been rendered, the Manhattan skyline for the Avengers climax had already been completed and was undergoing 'up-conversion' (which I assume is for 3D, since I'm not familiar with the tech jargon), leading to the plan being scrapped. However, it does show readiness on the part of Sony and Disney to co-operate, meaning Peter Parker could yet take arms alongside Tony Stark, Steve Rogers and co. Still fancy your chances, Thanos?