Brock Lesnar versus Randy Orton is a huge match, a clash between two huge names who have never met in a big stage context. They actually came up together at the same time, so there's already a built in history. They were students together in OVW, and did wrestle each other down there in what were described as good matches. The reason for never meeting in their main event careers has been down to timing and circumstance. However, by not having the two men wrestle, it has raised anticipation for an eventual match taking place. There's still a sense of inevitability that one day Orton and Lesnar must wrestle each other. It is absolutely big enough for WrestleMania, and it would allow Orton to function in his more suited heel role.