Okay, maybe I'm just saying this because I love Christian, and I always have since he and Edge were dominating the tag team division. But come on. Christian only held the title for two days, and this is probably his last chance for a long time. No one deserves a real title run more than Christian, and I think he surprises everyone and walks out with the title.
What's standing in his way?
1) Randy Orton. Everyone knows he can do pretty much whatever he wants because Vince is in love with him, and he's only held the title for a month or two, so he's not likely to be happy about giving up the title.
2) Vince McMahon. In addition to him being in love with Randy Orton, he also hates everyone who has ever wrestled for TNA. It was a miracle that Christian got the title in the first place.
But hey, Christian isn't one to let anything get in his way. And by giving him a heel turn, they make it possible for him to beat Orton in a way that makes Orton still look like a god. There is no way that Christian was going to beat Orton clean, so the heel turn allows him to win the title and cheat a little to do it.
Also, SmackDown doesn't exactly have a lot of heels who are "champion material." Unless you count Sheamus or Mark Henry, but Mark Henry will never win the WWE Title and Sheamus is a joke (former champion, yes, but what's he done since that?). So with a lack of championship-material heels, they need Christian to stay in the title picture, and at this point the only way that can happen is if he wins the title.