The Vampire Diaries EP Kevin Williamson revealed that the search for Stefan is season 3 will be very different for Elena than Damon; One is trying much harder than the other and well, who can blame him ;) Plus, fans will get some serious exposure to 'Ripper' Stefan and Klaus' true intentions for his new wingman.
"Damon loves his brother, he can't deny that anymore, but at the same time, his relationship is building with Elena in a very nice way, so that maybe he's not trying as hard as he should to find Stefan," executive producer Kevin Williamson tells us, adding that Damon will feel guilt over that. As for Stefan, the ripper lifestyle will lend for some serious life contemplation on his part. "Will he ever be able to come back and how will Stefan and Elena save him if they do? It's really going to be about the journey for Stefan: What's Klaus up to? What's Klaus' use for him? It twists and turns in a bunch of different ways that are surprising."
Source: TV Guide