I get the feeling Lois might be falling for Clark faster than he is for her. He's so cautious and careful in this incarnation, and I get the impression he doesn't feel he's in a position to have a relationship. Certainly Lois's parents will be horrified at her having a relationship with a homeless boy.
Clark is no way ready for a romantic relationship; although, I'm betting he wishes he were. I believe he does like Lois but being focused on his education, garnering funds for college, his duties as hero to the homeless, and the fact that he knows that Lois is heading to Ireland in a few short months, he wouldn't want to pursue a relationship at this time. Also, he's still nervous about his powers and his ability to control them, that I could see him more worried about accidentally hurting Lois than anyone else. Plus, being homeless, I cannot see himself as someone Lois *should* have a relationship with. Nor can I see him being comfortable at the Lane house, whether or not her father is at home, so I wouldn't be too surprised to see him make a hasty exit. Dr. Lane would never approve of him for his daughter, because Clark is homeless, and Clark knows this without having ever met the man. He said as much from what he said to Lois about how she treated his friends at the soup kitchen.
I don't think Lois has figured out that Clark is homeless, but I'm sure she's pretty close to figuring it out... especially after that interaction with the boy at the library who Clark referred to Brother Wayman. Clark's never hidden it, per se, but he's never announced it either. It's going hit her like a strike of lightning and, suddenly, everything she's learned about him will make sense. I'm interested to see in which direction and manner her freakout will happen (whether it's external or internal).