So there was a pretty cool reveal for Sombra at blizzcon just now. They were showing some video of the launch of Overwatch at Blizzard, with several engineers in a room ensuring the servers were running smoothly. Through a series of video glitches, this presentation was interrupted, and transitioned into this cinematic featuring Sombra:
https://www.youtube.com/watch?v=Og5-Pm4HNlI
Pretty cool way to introduce her in my opinion. They also put her hero breakdown video up on youtube:
https://www.youtube.com/watch?v=bcrPuSRYA4U
And finally they added her character profile to the official overwatch site. She is a stealth hero with an ability to make her invisible. She also has a "translocator" straight outta Unreal Tournament. Same name, same utility. Although, I'm not sure it will be able to telefrag people...
https://playoverwatch.com/en-us/heroes/sombra