I read now at wmpoweruser.com that with threshold update dur in spring 15 side by side Windows are coming to Windows phone
It could be possible, but the nature of phones (portrait) puts it at odds with the landscape nature of snap, so I doubt it, but eh, if they do it right, why not.
They can do it in portrait too if they want to do so... Like one window at above and the second window downside
thing is, the snap apps are able to be shrunk horizontally, not so in portrait. I sometimes use my Dell Venue in portrait and snap won't work.
It's going to take massive retooling of most apps if they want to do that, at least that's what I believe.