Mommy Star

When Simon Cowell signed Britney Spears to a contract to be a mentor on X-Factor, he, most likely, rightly assumed he'd be getting the pop superstar/legend that's sold 60 million albums (give or take) in the US. However, he, maybe not so surprisingly, ended up with Britney the Mother.
It would have made sense to assume that Britney, being the Queen of Pop, would have expected everyone to be as amazing as she is and never settle for less, to even be overtly critical of her own group. But it's really been the opposite. Britney never said one negative comment about any of her teens the entire show. No matter how poorly they performed or how negative the other judges were, every comment from Britney stayed positive and included such lines as, "I'm so proud of you" and "That was amazing."
When you think about it, what she said was no different than what any mother tells their young children. No matter how unrecognizable their drawing is, no matter how many times they struck out, no matter how bad whatever you let them cook tastes, you always tell them whatever they did was amazing. It's almost like a reflex.
Remember when Simon said something unflattering about Beatrice Miller? Britney quickly defended her by saying she had more talent in her pinky than all of Simon's groups combined. The comeback was clearly ridiculous, but it's what a mother says when her baby is insulted. Plus, Beatrice's huge smile showed how much she appreciated Britney standing up for her.
Would it have been more fun if Britney were more critical, more demanding? Maybe, maybe not. But it wouldn't have felt as real. I'm sure she spends most of her day telling her sons something that did was amazing. It's probably much more natural for her than sitting on some imaginary throne that her fans love to pretend she sits on judging people.
None of Britney's teens won X-Factor, but she was clearly the best mentor. The top 10 consisted of four of Britney's acts. She took Carly Rose to the finals. All the while, she kept a positive attitude. Some people hated her stock quotes. But this is what mom's do, they repeat stuff. Britney just did what she's been doing for the last seven years.
Perhaps Simon is secretly disappointed in Britney's performance. But this is who she is now. She's a mother first and you can't just turn those instincts off. She's not mean, and she probably never will be.

A Rose By Any Other Name

Britney's last remaining mentee, Carly Rose Sonenclar, has had her share of ups and downs. Of course, most of those downs involved people butchering her name: Carly Rose Sonenblurg, Carly Rae, and Carly Rose Sonaclar (even Britney screwed up when she accidentally announced Arin Ray's name instead of Carly's). Thankfully, her ups have far overshadowed her downs.
Since day one, she's been one of the favorites to win it all and has ranked in the top two every single week (along with Tate Stevens). Every performance she's given has been almost flawless (or flaw free, if you will). It's legitimately amazing to think she's not even in high school yet and she out-sings people twice her age (or in the case of Tate, almost three times her age).
It's almost a dead certainty that she makes the final three. The best part is, even with Britney and all her fans behind her, she's earned it based on her singing ability. Britney's asked people to vote for her, but she's been good enough that she could probably get by without it.
It would be pretty cool if Britney's mentee won, especially for Britney's fans. But it might be even better for X-Factor. If they want her back for season three, her winning would be a great starting point in negotiations. It would be easy to convince her that she did such a great job by mentoring the winner that she should come back and try to do it again. People love to win.
As for CRS, it's impossible to know if she'll have success once the show ends. Britney won't be there any more to guide her and walk her through the mine-field that is the music business. Of course, it's quite possible she doesn't need Britney. It's also quite possible that Britney becomes so attached to Carly she offers to help with her debut album (writing, producing, or getting her writers and producers to work with Carly).
So, even with a name that's been butchered by both Mario Lopez and Khloe Kardashian, Carly's shown that she can be the butcher, too. And, really, a Carly Rose by any other name would still crush the competition. Just make sure you spell her name right, X-Factor, when she wins.