Valeera in development video released, she and PTR arrive tomorrow.

After a handful of sneaky hints, Valeera shows up and will bring the PTR with her.
A sneaky surprise
We should have suspected Valeera Sanguinar would be sneaking into the Nexus earlier than expected. I mean, she is a Rogue, right? We found out on January 13th that she would be arriving through Blizzard’s official tweet.
It makes sense that Valeera would soon be following Varian, considering their history together. Valeera may be famous to you from Hearthstone or perhaps through World of Warcraft, but for the uninitiated, sate all your lore questions here. I have to say, I’m more than curious to hear the interactions between Valeera and Kael'thas.
This morning an in development gave us a peek into Valeera's kit:
Talents:
Although we won't know exactly how her traits work until PTR patch notes come out, here are some speculations based on what we see in the video.
Trait: Vanish
It seems Valeera can become invisible for a period of time. In this screenshot, you can see we have a little silence bubble on hit, which seems to imply Valeera's trait or perhaps a talent involving the trait can eventually silence targets. She is a Blood Elf and, per WoW, they have always had the ability to silence their enemies.
(Q) Sinister Strike
Dashing forward a short distance and doing damage, passing through minions. It appears that Sinister Strike can be used as a mobility tool, as well, similar to Greymane's Darkflight and Go For The Throat.
(W) Blade Flurry
A flurry of blades that stuns the target. If it stuns just one target or all targets in a AoE, we have yet to know.
(E) Eviscerate
A damaging hit that seems to be an attack similar to Artanis’s Twin Blades, which causes your next auto attack to happen immediately for a bursty hit of damage. The attack looks like it can only be used in immediate melee range, so enhancing her next auto attack seems likely.
(R) Smoke Bomb
Drop a bomb that creates a cloud of smoke in a decent-sized area, possibly limiting range of vision of enemies or possibly making you and allies untargetable within. Similar to WoW, Smoke Bomb makes people out of it unable to see inside, and people inside unable to see out.
(R) Cloak of Shadows
It’s hard to tell exactly what it is, but it seems Cloak of Shadows may be an enhanced Vanish; perhaps with true stealth, similar to Samuro. From the video, it looks as if you become untargetable and invincible for a short time. This would make sense, as once again, in WoW, Cloak of Shadows gives you immunity to magic snares, roots, and anything else that would stop you from moving.
No doubt a sneaky silence might make for some interesting new team compositions. But will Valeera manage to put a dent in the Warrior meta? With a hero like Valeera, it's all about the numbers. She seems to bring a decent amount of utility in the form of stealth, a silence, a stun, and Smoke Bomb. However, the true test will be her damage numbers.