Marvel held an exclusive panel for Unlimited Plus members where footage from The Avengers 2, Ant-Man, Agent Carter, Agents Of S.H.I.E.L.D. and the Guardians of the Galaxy animated series was showed off.
According to various reports, The Avengers 2 footage was the same that was revealed earlier in July at the San Diego Comic-Con.
The Ant-Man movie footage is described as Hank Pym talking to Scott Lang through his helmet with Ant-Man running through the streets, with Pym telling Lang how to control a fly that will let Lang take the fly wherever he wants.
My review of the Avengers: Age of Ultron clip that @AgentM showed us: