If they did bring back Ice Climbers it would probably be solely for Wii U. Unless they figure out a way to make the AI act as it should on the 3DS version.
Personally I want to see more Sonic characters like Shadow or Blaze. Hell I'll even settle for Tails. Also with the huge amount of love for Ridley and K. Rool I think it's likely that they'll be at the very least greatly considered.