It's always nice to see a new hero get added to the Ore Mall, because normally they turn out to be pretty good (both Alchemist and Spirit Arbiter are top tier, so I like that Vile Songstress is continuing that trend).
A guy named Andy uploaded a gameplay of him using her earlier onto the forums, and from what I can tell, Vile Songstress is basically an upgraded Wight. She doesn't kill the creature as fast (at level 1. Presumably, she'll kill the creature a lot faster at higher levels), but while the creatures are dying, they can't do anything. I'm not sure if that's a bug, though, because according to her skill description the creatures should only be disabled after they reach less than 20% of their Max HP. But in the gameplay that I saw, they were disabled as soon as Requiem hit them.
I like the name "Requiem", by the way. It reminds me of Siegfried's sword from Soul Calibur <3
If you are itching for a new hero, Vile Songstress is a pretty good choice. She's good even at level 1, and I definitely see her being even better at higher levels.
I think it's important to point out that so far, a Human, Mortii, and Neander hero has been added to the Ore Mall. So we can probably assume that the next hero to get added will be Faen :)