Update 13 Jul, 2016: The mystery has been solved further by using the differences between a second discovered code and the original which spells out - you guessed it - SOMBRA
With some more work overnight and the use of both the code seen above from towards the end of the video and another from nearer the start, further hints at Sombra have been found. This is probably the end of this particular mystery.
For everything else new, here's the low-down on Ana Amari.
Here's the second code, from 1:16 just as Widowmaker shoots Ana, colour shifted again to make it clear:
This one was a little harder to notice, hence it being discovered second. It has a few key differences with the original, a few spare numbers. If you take the last four from here, and the first two from the one later in the video, it spells out SOMBRA. This revelation has its own Reddit thread if you want to follow along.
Our dedicated new Overwatch heroes post has everything else you might want to know about Sombra.
Original story 12 Jul, 2016: If there's anything we've learned about Overwatch, it's that Blizzard are never doing just one thing at a time. Even in their own trailers, there are teases. The numbers you see above, colour-shifted to be a little more visible, are present in the Ana Amari Origins lore trailer that was released today, just as the screen fades to white for the final time. They were spotted by a Reddit poster, and have now been analysed. While the hexadecimal code doesn't directly translate into anything, some number wizardry gives it a clear meaning.
If you want to catch the numbers for yourself, direct your eyes here at just after 2:11.
So, what does it mean? Well, as always, the maths wizards of Reddit to the rescue. One poster took the numbers and applied the mathematical affect xor, which I'm not going to pretend I understood at university or anywhere else, with the modifier 23. They got to that modifier via trial and error to produce something readable, however it's worth noting that the next Overwatch character will be the 23rd - so it makes sense.
That spat out a series of letters and numbers which, once you removed the garbage, had this written there:
"la que tiene la informacin; tiene el poder..."
Translate that Spanish literally into English, you end up with "which has the information; It has the power..." Apply a little bit of knowledge of the language and translation skill, as several Redditors did, and you end up with "She who has the information, has the power."
Alright, so who is she? Spanish language? Mysterious entrance? A little bit sinister? This has Sombra, Overwatch's other heavily-hinted at character, painted all over it. We've broken down every bit of info about her in our dedicated new Overwatch heroes post, but all you really need to know is that she's been so heavily hinted at but remained so shrouded in mystery that it's only become clear that her and Ana Amari aren't the same person today.
That's everything ... for now. More secrets might be revealed as eager fans frame-by-frame trailers, dig into source code and repeatedly ask the official Twitter account what the deal is.