1) Remember that at the last rose ceremony, Jesse took no time in picking the first person - Tara. Then he took a long pause (thinking?) before he picked Jessica. Seems that Jesse has no doubts about picking Tara, but may have some second thoughts about Jessica.
2) He may have been setting Jessica up for the eventuality with that comment "I'm also falling in love with another woman," so that she doesn't take it too hard when it comes.
3) The producers may have purposefully showed a negative side of Tara's family (didn't show her Mom and showed her Dad in a belligerent mood) to catch the viewers on the wrong foot. Jessica's family seemed normal and I'm sure Tara's is too (though they didn't show that on TV).
4) Jesse tried really hard to open up Tara last week. Why would he do that if he is not seriously interested in her. He could have easily cut her last round because she was hard to read, but he didn't.
5) Don't forget that guys like women who are enigmatic, mystical, and a little hard to crack. Tara is one of those; Jessica reads like a open book.
In any case, whoever Jesse picks, I don't think either relationship will last beyond 6 months, given the failure history of prior Bachelor/ettes.