Speculation has been rife all week that WWE have "set in stone" the main event for WrestleMania 31 on March 29, 2015 at the Levi's Stadium in Santa Clara, California which will see Brock Lesnar defend the WWE World Heavyweight Title against Roman Reigns. 

Furthermore to that, WWE are looking to finalize plans regarding main events involving two special stars, likely The Rock and Sting.

WWE is currently building toward a match between The Rock vs. Triple H, although Sting has noted Triple H would be his second choice if he couldn't have a match with the The Undertaker.

Another match that has been discussed is John Cena vs. Rusev.

While the speculation suggests the main event is "set in stone" it would be too early to confirm any of these matches five months before the event. In all likelihood there will be several significant changes right up until the last moment.