The latest word on Sting and WWE is that they are hopeful to get a talent contract signed before SummerSlam. Sting is coming to Los Angeles for SummerSlam weekend but is not currently scheduled for the show itself.
Sting currently has deals with Mattel and 2K Sports but not a wrestling deal with WWE. Talk of Sting signing with WWE has become a running joke, among fans and wrestlers, because the two sides are basically in the same spot they were in when talks first started getting serious in January.
Sting has had talks with Vince McMahon before but never met him in person. Their first meeting will likely come during SummerSlam weekend.