Marvel's Kevin Feige weighed in on the rumor during a conversation with Comicbook.com. Usually pretty stingy with info, Feige was bluntly honest about the idea of this happening...
“No I mean we’re certainly having conversations about the future of all of those Fox properties,’ said Feige. “How to weave them in and when to weave them in. That one, in particular, is not the case.”
Depending on how the future shakes out with Sony and Disney, I could still see a teamup movie happening. Spidey and Deadpool share a similar sense of humor even if one has more of an R-rated edge. It's not too far of a stretch to see Deadpool toned down to be PG-13 accessible, though. They are frequently paired up in the comics, much in the same way Spidey was often partnered with Human Torch, who also has a jokey sense of humor.
So maybe someday we'll see Spidey and Deadpool crossover, but now ain't the time.