As much as I get tired of bored of Cena...
I would LOVE to see a Cena vs Taker at the 30th Anniversary of WrestleMania. Just thinking about it, its a milestone for the WWE and what would be a better main event than having the TOP WrestleMania guy facing off against the TOP guy in the WWE? The billing would be epic. I see it now, the poster... the purple hue, the WrestleMania Logo over New Orleans.
WrestleMania 30
John Cena vs The Undertaker. Where else can either guy go? They have already beaten everyone plausible and possible at Mania. WWE Would be smart to book this, for many reasons - it would give WM a MUST SEE feeling (to me at least) it hasn't had since the days of Hogan.