If he had any kind of inkling that Sam was back [no matter what incarnation] he would definitely seek him out. Depending on what that encounter was like [ie if Sam was just Sam and wasn't in any trouble] Dean may go back to Lisa.

good question!

probaly

Dean would go to Sam...at least I hope so. This show is based on the brothers and their love and devotion to one another. Not based around them and their relationships with chicks lmao. If next season focuses even a little on Dean and Lisa I will be very disappointed.

if you're talking about season 5, i have no idea what you're on about, so i can't pick....lol

Good Question!
But Hell No!!! UGH i HATE that Bitch anyway!!but thats not the point!!
SAM is his Brother and if he Knew that he's out there he'll GO look FOr Him!! Cuz were talking about he's own Brother!!
he Sure wont Stick with lisa He may love her and care 4 her so much but not as much as sam!! Right?!
Mybe after he do Find sam he may come back to lisa! if there was nothing wrong with sammy!!

Do you really expect Dean to settle down into some normal, apple-pie life when he knows his pain in the ass little brother is alive somewhere? No way!

Of course he will!!!

oh, come on, dean would not have stayed with lisa if he knew sam was back... i mean, he made a promise to sam, but that won't stop him from being with his brother again....!!!!!!!

With Dean Sammy comes first before anything. He has shown this to us plenty of times, for example selling his soul.