Players are already able to fly with Creative Mode. However, the new cape allows you to do more than just float around. You glide through the air, picking up speed as you dive and then slowing as you climb. It seems more, for lack of a better term, real. Here's some short footage of the flying cape posted on Twitter by Mojang's Jens Bergensten:
Ok, here's a gfy. And as always, work in progress! https://t.co/vY92PB2j1u (for 1.9, Java edition)— Jens Bergensten (@jeb_) October 6, 2015
More info! Not craftable, only found. Here's a gfy of 3rd person mode with Mojang cape texture: https://t.co/kpIVyxuMsj— Jens Bergensten (@jeb_) October 6, 2015
They fold when you land and replace the cape (if any) when equipped. They are styled as the cape + new Mojang cape: http://t.co/FoFsY0zu6Z— Jens Bergensten (@jeb_) October 6, 2015
This week’s snapshot brings you the ability to smash out of the window of a high tower building, fly past the bad guys who are all shooting you with surprisingly bad accuracy, swoop down and land flawlessly into a strategically placed boat and then paddle away at moderately high speeds with the stolen prize pig in the back.
You can find the instructions for downloading and playing the snapshot at Mojang's website. Because it's an in-development patch, you may run into some bugs. However, I think the bugs are offset somewhat by the ability to soar through the air like a bird or super hero.
Mojang hasn't said when flying capes could come to the Xbox, PlayStation or mobile editions of Minecraft. Given how highly anticipated this feature is, I imagine we'll see it on those platforms eventually.