Actually, there has been a huge amount of serious research done in Lower Nubia and the Sudan since Ballana and Qustul (which, BTW, were excavated closer to 70 years ago), on all periods from the Paleolithic right up to the Christian. Perhaps you are not aware of it. Some of these researches were indeed the heritage of the High Dam Campaign, when archaeologists like W.Y.Adams and Fritz Hintze got hooked on Kush and just stayed on, but Sudan studies really took on a life of its own from the 1960s onward.

And, contra to some of the comments below, the Sudanese government is very supportive of foreign teams, and the Sudanese archaeologists are valued colleagues. The government is, in fact, eager to develop archaeological tourism, while also preserving the sites, though they suffer from a shortage of resources and funding. The only specific restriction placed on foreign archaeologists, as far as I know, is to keep off Islamic sites, and particularly Islamic burials.

As for the Fourth Cataract salvage efforts, Khartoum positively encouraged foreign expeditions; though somehow Merowe seems to lack the glamour of the Aswan campaign, and the international effort has been somewhat hampered by the usual funding difficulties. Trouble has started up in the area, though, because the people who are being displaced are not happy with the compensation from Khartoum. There was some violence last year, and some of the teams had to leave the field early for their own safety - not sure what the situation is for this season.

BTW, I thought it was a great article.