The potential Cara/Chavo fued sticks out to me just because of how they laid the foundation for it on this week's show. It wasn't just a bogus run-in attack from Chavo, it looks like it will be slowly built up over the weeks. I'm looking forward to what those two can offer together, and because Chavo hasn't been involved in a fued for WAY too long (vs Hornswoggle doesn't fucking count).
As for Orton vs Christian.... I'm REALLY hoping this will lead to a Christian heel turn, for three reasons:
1. WWE are low on credible top heels right now
2. If he doesn't, who else is there on Smackdown? Sheamus? Mark Henry? No.
3. Christian is just an awesome heel and he hasn't been heel since before TNA.
Judging from Christian's show-closing reaction, either WWE are teasing us, or he will gradually begin to get darker until he officially snaps on Orton (kinda how CM Punk was slowly turned heel while fueding with Jeff).