I struggled to give this a 4-star but I thought it was better than a 3-star. I wouldn't recommend this movie to a really close friend but all you others can go watch it.
Like others have mentioned, the families were structured like Mahabharata and some characters were loosely similar but in my mind it was closer to the movie Godfather. There was ruthless ripping off of Godfather characters and scenes right from the main character Samar (aka Michael Corleone) to his pregnant girlfriend (Michael's wife in Godfather) to his elder brother (remember the toll booth scene in Godfather?). Also, the movie was looonnggg inspite of having only one real song sequence.
That being said, the acting was outstanding by all the artists. It's hard to name the "best actor" award in this movie coz everyone played their part to perfection. Kudos to Ranbir Kapoor, Arjun Rampal and Katrina Kaif who in my mind were the least "seasoned" actors in the movie. You always expect awesome performances from Manoj Bhajpai and Nana Patekar and they didn't disappoint. Even Sarah Thompson played her role very very well.
For what its worth, if you do go to watch this, pay a visit to the mens (or ladies) room, buy some popcorn and a coke before you go in.