Prediction: Carrie Underwood may go into Adult Contemporary genre
This is something that has been interesting to watch over the course of Carrie's career in the last 8 years because Carrie has always carefully planted herself between the country and pop fields. However, if history is to be believed, I think with her 5th album - possibly going to be released this year - she's going to take a bigger approach towards soft rock. If you look back at the women who have come before her, you'll see that artists like Faith Hill ("Cry", "Breathe"), Shania Twain ("Forever and For Always", "You're Still the One"), LeAnn Rimes ("I Need You"), and even Martina McBride ("I Love You", "This One's For the Girls") have all had their small time on the Adult Contemporary charts. With that being said, all of those great country ladies were considered at the top of their game in the country genre before crossing over to AC and gradually fading out.
A similar thing is happening to Carrie. If you look at the number of awards or the number of records she's been able to sell over the course of her career, you'll see that the numbers are slowly falling. That's common enough for all artists. But there are artists like Miranda Lambert who have taken over Carrie's "Queen" spot in country music and now Miranda is winning all the awards and getting the bigger airplay on radio.
Going into AC/Soft Rock would be a great move for Carrie, I believe. She's worked with Tony Bennett ("It Had to Be You"), she's collaborated with Steven Tyler, and she's also toured in countries that place less emphasis on country music and have more of an open audience to AC (England, Australia). Let's not forget she's been in The Sound of Music, which helped take the emphasis off her country roots and showed that she can sing just about anything.
Also, look at Shania Twain. She landed a great gig in Vegas. She isn't just a country artist - she's an AC artist too. The same could be said for Faith Hill. Carrie will probably fade in a similar fashion that these ladies did - gracefully and slowly. And they haven't really gone away, either. Shania and Faith still get played and everyone still remembers them as great artists.
Taylor Swift is an interesting phenomenon because she's been able to not only place herself in pop and country, she's also placed a few songs on AC radio ("You Belong With Me", "Love Story", "Everything Has Changed"). Lots of Taylor's songs from her most recent album could also fall into the soft rock category. Carrie and Taylor have been compared many times, and I also believe we will see Taylor Swift drift into AC when she gets older.
I think Carrie can replicate the success she had with "Before He Cheats" (which actually did well on the AC chart despite the fact that it sounds country as heck and it out of place among most other AC songs). She has quite a bit of soft rock songs that could have been released to AC radio, and I think one single that actually was ("Some Hearts"). Look up "That's Where It Is", "Twisted", "See You Again", "Who Are You", "Unapologize", and "Good in Goodbye". All of these songs are certainly not entirely country, with enough soft rock hints that they could fare well on AC.
I think Carrie has slowly been building her way up towards a move to AC and I think we just might see more of that side with album 5. Sure, there will be one or two country songs for country radio, but I think she will start expanding her audience to appeal to a wider range of people (and let's not forget her fan base is growing older). She has always expressed an interest in rock music and she sang with The Rolling Stones last year. She's also covered rock hits like "Paradise City". Some of her previous material is on the rock side of the spectrum ("Good Girl", "Cowboy Casanova"). I think she has also been smart to branch out and work with writers like Max Martin, Kara DioGuardi, and Ryan Tedder so that she isn't limited to country songwriters.
Most American Idols have placed a song or two into the AC/Pop arena (Kelly Clarkson, David Cook, Jordin Sparks, Phillip Phillips), so Carrie is all set for a move. I think she has enough appeal to broaden her horizons and see a rewarding response from new listeners. The country music scene has all but shut her out for Miranda Lambert (possibly due to the fact that with songs like "I Know You Won't", "Blown Away", and "Lessons Learned", Carrie has never neatly fit into the country slot) so she would not burn many bridges that she hasn't already burned. She's a gay marriage supporter and a vegan, for crying out loud. Country fans don't exactly relate to her lifestyle. Oh yeah, and she married a Canadian hockey player.
So I think Carrie will balance her sound somewhere between Celine Dion (too dated and dull) and Miranda Lambert (the new darling of country as of 2010). That leaves her in Faith Hill/Shania Twain territory, a place I have always imagined her to be.
And one last note - AC is great about playing new Christmas music, and Carrie has tried her hand a couple times with Christmas songs. She has yet to produce a Christmas album itself (like Celine), but I predict we will see one from her soon enough as well.