I was really bitter about how Quan Chi had just butted in and taken over alot of the plot points of MK9. I didn't feel he belonged there, but should rather stay in the background and pull the strings. So I had a major dislike for Quan Chi for a long time, and before MK9, I actually liked him.
After having seen this trailer... I actually kinda like him again. He looks cool, his moves are rather cool... It's not the reveal I wanted, but hopefully they will come later.
So what do we know? He seems to have abilities that would fit Shang Tsung and Noob Saibot, so they might not return. Scorpion has a variation where he summons demons to help him, kinda like Noob did with his shadow, so it does indeed point to Noob not returning for MKX.
The Summoner variation reminds me a bit of Nakoruru and her hawk in Samurai Shodown, which I find rather interesting.
Overall a good job on ol' Quan Chi, imo. ^^