Samsung isn't going to settle when it comes to their display of choice on the unannounced Galaxy S5. According to Tencent it appears that Sammy has chosen to go with Sharp's 5.25" 2K Ultra HD 560ppi LTPS display panel in place of their own 2K AMOLED. Tencent claims that the reason is that Samsung's SDI subsidiary has encountered production/yield issues with it's own 2K AMOLED displays, and they simply cannot make enough of them to meet the projected demand for the S5's sales volumes. They also mention that Samsung is focusing its attention on getting its flexible AMOLED into full production with mass market distribution by 2015, thus forcing them to turn to Sharp for their 2014 flagship screens.
Will Samsung's top tier handsets all come equipped with Sharp's screens? That is yet to be determined, but seeing that Samsung has a 3% stake in Sharp, its a pretty safe bet that Sharp's displays will be the display of choice until Samsung can get production/yield issues ironed out.