Hu has marshaled much of his political capital to promote his top protégé, Li Keqiang, already in the party's inner circle and executive vice premier, as potential successor.
Whether Hu can install Li ahead of Xi Jinping, who is regarded as Jiang Zemin's choice, is deemed a measure of Hu's strength.
Li is expected to move to the top, but not as Hu's successor as paramount leader.
Xi, 59, was elected last week as the ad hoc secretary general of the congress proceedings, another signal that he is firmly lined up to inherit Hu's top posts.
The only question that remains, experts say, is when Xi will take up the CMC chairmanship.
"Xi's position will be enhanced if Hu steps down now," said Wenran Jiang. "He can assume full institutional power. Of course, that will not change the basic dynamics that Xi is a team leader in a collective decision-making system. He will have to build consensus for any major policy initiatives."
Such a consensus will be even more important if Xi intends to pursue significant political reform measures.