[thh00]

Well, Yad's internal structure is more like the French Socialist party. It allows for currents inside it. Those currents are based on different lectures of history, politics and philosophy. Thus, I cannot say that there is a mainstream ideology by which everyone should abide. It is one of the major differences that Yad wants to create with the old-school of left.
Another reason why I cannot answer the question directly is that Yad is not marxist in the sense where marxism is taken as an ideology. Yad agrees with the marxian methodology of analysis, and believes that Marx is a major contributor to the left ideology but refuses to consider Marxism as the only scientic socialism as Marx claimed that he was.

When it comes to Samir Amin, I think that Amin has a very interesting perspective and saw right that there is a relation of dependency between the center and the peripherals (3rd world.) Amin also grasped what he called statism (al-dawlana) in the soviet union as a dominant mode of production. He said that the communist countries had three contradictory tendencies: capitalist remainders, socialist dreams and statist factual. He had the guts to criticize the soviet union from a leftist perspecitive and has had a contribution to the arab left and the world left. I think that Amin has made good points in the above mentioned; however, when it comes to the solution of breaking the dependency (fak al-ertibat as he calls it) I disagree with him totally. Amin himself rejected later this theory. I also disagree with Amin's latest publications where he claims that the military tendency of the US is a sign of weakness and the beginning of its dawn. I think that he has been lately caught up in his illusions.
One last comment is that I tend to agree more with people like Mehdi Amel in his analysis of the dependency or the (neo-colonialist modes of production) than with Amin's analysis
Hope this clarifies
P.S: the part about Samir Amin is my own stance