As noted before, the WWE were planning on a McMahon family feud for Wrestlemania. The feud was supposed to unfold at SummerSlam, with both Triple H and Mr McMahon currently at loggerheads over various issues.
The WWE wanted to involve Stone Cold in the angle to side with Mr McMahon to oppose Triple H, who was expected to turn heel. And a Triple H vs Stone Cold match at Wrestlemania XXX to determine who holds control of the WWE.
The plan proposed has not yet been agreed to, for reasons unknown. However, there are rumours making rounds that the WWE are looking at replacing Austin with The Rock.
Despite having no official confirmation yet on the issue, it is certainly clear that the WWE are planning for a major main event at Wrestlemania.