During their visit to Samsung's demo room at CES, AnandTech spotted a roadmap that could help confirm details about the expected Galaxy S IV. According to AnandTech, the poster seen above shows a series of current and projected AMOLED screens, with those under the "HD" heading matching the Galaxy S III and Note II in size. If the roadmap is correct, that means we'll be looking at a 4.99-inch full HD (1080p) screen with 440ppi in the first quarter of this year, in line with when we'd expect a Galaxy S IV.
We were already expecting a 1080p screen on the S IV, and the minor size bump from 4.8 to about 5 inches would fit with what we've heard about a Note successor larger than 6 inches. Taken together, there's not a lot of new information here — we'd have been surprised if the successor to the Galaxy S III wasn't trying to compete with current-generation 1080p screens. But if right, it does fill out what we know about the phone, as well as confirm the rough timeframe Samsung is operating within.