Is it just me or is booking Brock and Rock a year in advance, as you suggested, a HUGE mistake. First of all, this match didn't need the year of hype to make it big, in fact I could have settled with it being started at survivor series or even around the Rumble. Hell, during the summer of Punk I didn't think twice about this match. But anyways, the reason booking anything with Brock so far in advance is a mistake is because look at what happened in the UFC, brock had to miss two major fights because of his illness. Who is to say it won't strike up again around Mania and cause them to have to cancel a major match. The WWE was very lucky that this match was able to happen and Cena never got hurt despite working a full schedule still. Anything can happen between now and next year and so booking a match a year in advance is not something I think they should risk. I'm not sure where they can go from here now though because I don't see much value in a rematch after Cena lost the big one and has to go back to work full time, really sucks for him imo as I think he should have gone over. They do need to debut some new stars tomorrow, hopefully Albert and Batista come back to keep that night after mania excitement going.
I don't think it's a great idea to try and book any match one year in advance again. Cena was rear ended by a car that was rear ended by a semi truck two or three weeks. There are so many ways that could have went wrong. While his long term health and career is more important than one match, it would've threw a pretty big wrench into things. Orton, Christian, Wade Barrett, Del Rio have all messed time with injuries lately.