You've always been able to take flight in Minecraft's creative mode, but in a forthcoming update Mojang will roll out a new cape for the sandbox's Adventure Mode. This cape will allow flight, and judging by the animated .gif below it'll be a much more graceful and fluid mode of traversal than Creative's stilted method.
Check it out:
That .gif is via Mojang's Jens Bergensten. He Tweeted that the cape folds when your character is standing on solid ground, and is a findable object: ie, you can't craft it. It's due to come in the next Minecraft Snapshot, which hasn't been dated yet.
As you wait, why not check out this work-in-progress attempt to get Pokemon running in Minecraft?