Dave Meltzer provided an update on Sting in the latest Wrestling Observer newsletter. There still is no confirmation that Sting is signed with the company. I actually heard several weeks ago from people that know Sting that said they believed he had already signed his deal. That actually wasn’t the case. WWE signed their paperwork but the company is just waiting on Sting to sign his end of the contract.
There are said to be only a few people in on the contract negotiations so for all we know he could be signed. Regardless, whether or not he’s signed his deal it’s considered a formality and he’s considered to be part of the company. Sting appeared on the WWE Network specials honoring the Ultimate Warrior last week. They also plan on releasing a Sting DVD later this year.