For me, they will end up together. I am quite sure. Agar nahi hota toh story ki formaat hi aisi nahi hoti. After wasting so many months on Sameer-Naina's lovestory cvs just can't show that they are marrying some other random people. Cvs are not that dumb.
2ndly, Indian tele viewers are too sensetive. They won't accept new leads opposite Sameer or Naina, & then adha people will leave or stop watching the show...ab itna foolish toh nahi hai cvs.
The way this show is going its clear that Samaina will end up together and third person agar enter hote hai toh that will be only to add up spice and drama, and they are just in 11th right now, iske aage clg bhi hai...jahaan aur drama hai but sare dramas ke baad bhi it will be Sameer weds Naina.