-Lesnar vs Reigns
-HHH vs Sting
-Orton vs Rollins
-Cena vs Rusev
-Undertaker vs Wyatt
-Andre Memorial Battle Royal (will probably end up being the annual pre-show match from here on out, though)
-Some multi-man Intercontinental Title match mostly featuring a whole bunch of people who have no other place on the card but are still good enough not to get thrown into a filler battle royal if they don't have to (that would be Barrett, Ambrose, Ziggler, maybe Bryan and a returning Sheamus, etc.)
-Possibly Bryan vs a heel Sheamus if neither end up in the above match
-Probably a Diva's Title match of some sort. According to PWInsider, "AJ is expected to return to TV soon as creative as a storyline in place for her return.", so you can probably expect something involving her, Paige, Nikki and Brie.
Goldust and Stardust will probably be thrown into the battle royal and then left to finish off their rivalry for good in a stipulation match at Extreme Rules. Miz and Sandow will happen later as well. There probably won't be a tag team championship match this year either unless they fit it on the pre-show somewhere, too. Cesaro, Kidd, Usos, Prime Time Players, etc. will probably just end up in the battle royal instead. There won't be more than eight matches tops on the main card.