Coldplay has a new album coming out next year but I don't want them to pay it themselves. They are smart so it will depends on their labels (who are poor by the way) and how much money NFL wants. The Super Bowl halftime exposure is overrated anyway. It only translated in huge sales after MJ's performance.
But if they pick Coldplay, here is what they should perform
1. Clocks (perfect opener, the piano one
) (3min)
2. Fix You (a short version, 1min from the sad part, 1min from the happy part, sing a long part)
3. Viva La Vida (the live 2009 version, 4min)
4. Whatever song they performed with Jay Z and Rihanna at the Olympics (3min)
5. Single for LP7 (3min)
They'll definitely bring out Jay Z and or Rihanna but I would have them perform with guests.