It was reported back in the summer that WWE had interest in signing Sombra and now word is that he gave his notice to CMLL in August some time.
Several sources believe WWE has picked up a great talent in Sombra as he's known to be very professional. He carries a lot of pride but he's good at what he does and some feel he could be the top Latin star that WWE is looking for. Sombra has potential to be a big crossover star in the United States and speaks English well.
There's been no indication that he will wear a mask in WWE but "Dr. Lucha" Steve Sims recently noted on Wrestling Observer Live that Sombra may have more charisma without the mask. The feeling was that the mask made Sombra more generic and he had to work harder to overcome that.
Dave Meltzer of Wrestling Observer Radio backed up the reports on Sombra's character, noting that he won't rub people backstage the wrong way and has a good chance at making it as a big star in WWE.