Watched a stream from Blizzcon for a while, her "transposer" has a five second cooldown, which seems really short, but it has a long "cast" time as she physically throws it, and teleports to wherever it is when she presses the button, so I'm expecting to see lots of hilarious failed emergency Sombra escapes to two feet away in midair in the PTR.
Her ability to hack medkits seems incredibly powerful though, a huge shutdown for single healer teams and Tracer play. Not only does it prevent the enemy team from using that point for one minute, it also makes the medkit regenerate every five seconds instead of every thirty as normal. I'm betting that gets nerfed in some way before she goes live.