Update: new reports from Korea suggest that Samsung decided to stick with OLED technology for upcoming Full-HD displays...
ZDNet in Korea reports that Samsung will abandon AMOLED technology in favor of LCD for their next generation flagship phone (which will probably be called the S4). The reason given is that Samsung will have to use Full-HD resolution (to compete with Full-HD phones from LG and HTC) - and 4-5 inch AMOLED panels cannot achieve this resolution yet. ZDNet claims that Samsung is interested in buying these panels from Japan Display.
Hopefully this is not a correct report. Last month it was actually reported that Samsung did manage to achieve 400 ppi in their AMOLED displays, and that they will be able to produce Full-HD AMOLED mobile phone panels. In any case, it's not clear whether such a resolution is actually necessary in such small screens.
This will obviously be a major blow to Samsung Display, as most of their profit comes from OLED displays, and Samsung Electronics is the major customer. Samsung Display is actually increasing AMOLED production capacity and so they probably assume they'll keep supplying OLEDs to SE's mobile phones.