So far, Bruno is the only performer that has been announced. There were talks of there not being a halftime show because of the logistics of setting and then disassembling everything during a possible blizzard. But since it's going to be cold, it's likely it won't be a huge show. Just keep tuning into the Superbowl website here:
I already answered this in your original question. The Marching bands from both schools will most likely be performing. That's usually the tradition for the Rose Bowl. The game starts at 5pm Eastern Standard Time so halftime will most likely be at about 7 o'clock for 20 minutes but they usually don't show the bands performing (usually just game recap).
For the Rose Bowl? It's usually the Marching bands from both schools (Michigan State & Stanford). If you're referring to the BCS National Championship (or the "Super Bowl" of college football), it'll be Dierks Bentley on Jan. 6th.