Apple's CEO, Tim Cook, said that OLED displays aren't good enough for Apple - the colors are too saturated and the screen is not bright enough. "If you ever buy anything online and really want to know what he color is, as many people do, you should really think twice before you depend on the color from an OLED display", says Cook.
Back in September DisplayMate posted an interesting and comprehensive comparison between the iphone 5 IPS-LCD and the Super AMOLED HD display used in the Galaxy S3. Indeed the call Apple's display as the superior display. The color accuracy of Samsung's OLED is something that can be calibrated, and I'm sure that if Apple wanted Samsung could have made a very accurate OLED. DisplayMate does like OLED displays and thinks they have a great future (and they say that LG's OLED TV is the best TV they have ever seen).
We also know that Apple is interested in OLEDs, and the company already has several patents involving flexible OLEDs, OLED based BLUs for LCDs, OLED control schemes and others. Just last week we reported that Apple has hired a new executive into its Display group - Dr. Jueng Jil Lee, a former research fellow at LG Display, who apparently was involved with OLED TV printing technology research.
So yes, Samsung's current displays aren't accurate, but some people love the overly saturated colors as they look great. The current OLED displays aren't bright and efficient enough, but this will change soon (it is said that Samsung's next-gen AMOLED panels will be 25% more efficient, thanks to green PHOLEDs). Samsung's OLED displays will also soon offer a higher density than the iPhone's 5 display. Not to mention Samsung's upcoming YOUM display - plastic based OLEDs which will be thinner, lighter and virtually shatterproof. OLED displays will keep improving, at a faster rate compared to LCDs, and it's quite likely that we'll see Apple adopting OLEDs within a few years. We'll keep waiting in the meantime...
Regarding Tim Cook's comments about OLED not being good enough for Apple, this blog post predicts that Apple will not be using OLED for their TV because of Chemistry concerns rather than performance. http://flatpaneldisplay.blogspot.com/2013/02/chemistry-and-apple-tv.html