I'd say the age of aerial drones closes a chapter in the history of ufology. With the proliferation of drones, it will be so reasonable to discount reported sightings of UFOs as drones. Even if the observer was sincere, it will be so easy to chalk that up to mistaken identity–combined with the fact that SF films and ufology lore have fostered an expectation and preconception. We tend to see what we expect to see. What dovetails with our interpretive grid.
Short of the mother ship descending on the White House lawn, with shape-shifting reptilian aliens emerging from the craft to give a world press conference, I'd say future evidence for ufology based on reported sightings is doomed.
In principle, you could still have new stories about alien abductions. However, that trope has become such a well-worn genre that I don't see how additional stories will tip the balance. The question is whether you find that kind of claim to be credible or not.
Unless SETI starts getting hits, I think the fortunes of ufology now depend on the state of past evidence (such as it is), and rehashing gov't coverups.
Of course, as students of Hellboy know, ufology is actually a garbled version of something more prosaic:
In 1944, with the help of Russian mystic Grigori Rasputin, the Nazis build a dimensional portal off the coast of Scotland and intend to free the Ogdru Jahad—monstrous entities imprisoned in deep space—to aid them in defeating the Allies. Rasputin opens the portal with the aid of his disciples, Ilsa von Haupstein and Obersturmbannführer Karl Ruprecht Kroenen, member of the Thule Society and Adolf Hitler's top assassin. An Allied team is sent to destroy the portal, guided by a young Trevor Bruttenholm, who is well-versed in the occult. The German team is killed and the portal is destroyed—in the process absorbing Rasputin—while Haupstein and Kroenen escape. The Allied team discovers that an infant demon with a right hand of stone came through the portal.
Unfortunately, ufologists are dissatisfied with such a mundane explanation, so they go in search of far-fetched answers.