Idea on a Portal ultimate
Watching the Overwatch gameplay trailer gave me an idea for a new ultimate, though not a Champion to tie it to.
Warp Gate (tentative name)
Channel for 3 seconds to open a portal at target location (global range, but you must have sight of the location). If you finish the channel, the portal enables one allied Champion to use the portal to teleport to the location you channeled at (but not vice-versa). The portal closes if you are killed, after a few seconds, or once an ally uses it. Very long cooldown.
Think of it like a global-range version of Thresh's lantern, though with a lot more restrictions on its use and no shield mechanic. Tactics!