For Phase 3, Empire speculates, “More Iron Man/Thor/Cap adventures probable, plus finally, a proper Hulk standalone (Planet Hulk?). Ant-Man is a confirmed intro (November 6, 2015); planned intros include Spock-esque fishy-bloke Namor The Sub-Mariner and magnificently ‘tached magic-man Doctor Strange. Will end with Avengers 3 in 2018ish, which could see a super-angry Hulk’s return (World War Huk!).”
For most of their speculation, it’s easy to figure out where it arises from. Ant-Man is already announced, and Marvel Studios President Kevin Feige recently confirmed Doctor Strange for Phase 3. It’s pretty easy to guess that Iron Man, Thor, and Captain America will continue if their Phase 2 movies are successful, and Avengers 3 is likely a given. Of course, everyone knows where the Planet Hulk rumor originated.
What is surprising though is that they list a Prince Namor The Sub-Mariner movie in Phase 3, even though there hasn’t been much to hint that The Sub-Mariner will be getting a stand-alone movie that soon. In fact, most of the online rumors have centered around Black Panther being one of the next stand-alone movies announced, but Empire doesn’t speculate Black Panther until Phase 4.
Plus, it's also interesting that Empire puts a question mark next to Planet Hulk, while they label Namor The Sub-Mariner as planned alongside Doctor Strange (which was recently confirmed). Now of course, again, this is all admitted speculation on their part, but the surprising inclusion of Prince Namor The Sub-Mariner as planned in Phase 3 can’t help but make us wonder if they’ve heard a little inside info from Mr. Feige.