There was an interview during the strike, I forget if it was with Kripke or with Sera Gamble, but they had said that there was a possibility that they would actually resolve Dean's storyline in the beginning of S4.
I'm remembering it differently... I thought I read that they planned to wrap up Dean's storyline by the end of season three. On the other hand, my brain has slowly been turning to mush, so I may be wrong.
I'm unspoiled for the next two eps, but I can't see any other way than for Kripke to end the season with Dean dying. What is going to be his other cliffhanger? Now episode 4.1 may be Sam going to the crossroads and selling his soul, but getting Dean out of the deal is going to be resolved in season four. I'll gladly eat my words if Kripke makes me wrong.
My expectations are lower and I am enjoying the heck out of the episodes. However, now that we are at the end of season three, I can say it hasn't been my favorite season. There were some great stand alone episodes but, strike or not, something was missing. John, Mary, Missouri, Jess, YED, Ellen... I'm okay if we don't learn anything new in the next two episodes. More questions to set up something for season four maybe, but I don't expect any answers.