With the death of Saudi Crown Prince Sultan and he elevation of Interior Minister Prince Nayef, 78, to the position of heir to the throne, speculation resumed, naturally enough, about when the Saudi throne might pass to the generation of the grandsons of the Kingdom's founder. Since the death of the patriarch King ‘Abd al-‘Aziz Al Sa‘ud (the man the West called "Ibn Saud") in 1953 — 58 years ago — all five Kings of Saudi Arabia (Sa‘ud, Faisal, Khalid, Fahd, ‘Abdullah) have all been sons of his; the grandsons' generation have grown gray and, while holding many key positions, have not been positioned in the line of succession. The elevation of Nayef to the post of Crown Prince makes clear that (assuming he survives King ‘Abdullah), there will be at least one more King from the older generation.
But the announcement over the weekend that Prince Salman, Governor of Riyadh for decades, would succeed Sultan as Minister of Defense and Aviation makes it likely that he, too, is being positioned to succeed. One of the seven "Sudairi" or "Al Fahd" full brothers (including Fahd, Sultan, and Nayef), Salman is respected and influential. He had not, however, held any positions related to security or external affairs; the Defense Ministry fills that gap.
The key to watch for would be if the King designates him as Second Deputy Prime Minister down the road. Every King since Faisal has been his own Prime Minister, and the Crown Prince has been the First Deputy Prime Minister. In most cases, designation of a Second Deputy Prime Minister implies that prince will be next in the line of succession.
Prince Khalid bin Sultan, who had effectively been running the Armed Forces under the long-ailing Prince Sultan, was designated Deputy Defense Minister, so Sultan's family influence in the Ministry does not disappear.