Well, it happened. Mark Zuckerberg held out as long as he could, but even he had to crack eventually.
Facebook just added GIF capability to "Boosted Page" posts, which make up the majority of the company's biggest advertisers—so you can expect regular bursts of looped-motion ads glutting up your newsfeed from here on out. The first two companies to take advantage of the new policy were Wendy's and Kuat (a Brazilian Coca-Cola subsidiary).
Wendy's ad, featuring one of its salads, coming to life, then disappearing.
Kuat's ad, featuring the Nyan Cat meme, in all its multicolored glory.