It sounds like they will be performing Bon Jovi songs as per these comments from an EW interview:
What did the judges mean when they said he lacked some of the country twang he had the week before?
I thought he still had that country edge. Plus Garth Brooks is so country-pop crossover. Phil's going to bring that to Bon Jovi next week as well. He needs to do that. That's who he is. That's the record he could make.
What can we expect from Bon Jovi week?
I think the guys definitely have an advantage singing Bon Jovi songs. Whatever the girls do, they should get extra props for having to sing a guy rock & roll-vibe song.
You're working with Chris, Phil, and Jordin this week. Has the theme been tough on Jordin?
It's tough for all the girls, though I can't speak for Melinda and LaKisha because I'm not working with them. What I will say about Jordin is that the second it was announced we were doing a Bon Jovi week, she requested her song early. She knew exactly what she was going to sing.
Whole interview here:
http://www.ew.com/ew/article/0,,2000...037172,00.html