The main advantages of OLED stem from the fact that the technology uses an organic polymer based diode process to create light of the specific color required directly from electron jump events that occur between two materials selected to produce light of a specific frequency. Much like the LED lights that we are all familiar with from their use in power indicators on all sorts of products this method of light production is extremely efficient compared to CRT and Plasma.
Additional advantages of OLED technology lie in the fact that the purity of the produced light enables high gamut displays with very accurate color. Also since light is produced only when it is needed, OLED displays have very high contrast ratio's while offering very high angle of view (unlike LCD's which have significant light fall off due to masking elements in the LCD layers) just like older CRT's. The parsimonious production of light as it is needed and the creation of that light from specific pixel elements means that OLED displays are amazingly power efficient compared to any other technology save for passive technologies like e-ink.
Thus coupled with the requirement for TFT (thin film transistor) backplanes to define the pixel grid of the display, the OLED display technology offers superior performance to the older technologies but comes at an advantage in the characteristics mentioned providing a strong incentive for consumers to purchase the technology (at appreciable cost) over the other technologies once it is released. The strong list of advantages will provide a great impetus for the display manufacturers that plan to start mass producing OLED displays to move to the technology as quickly as possible to take advantage of the strong demand that will arise from the consumer space for such vastly out performing displays.
Currently, small production numbers on small screen areas have shown the power of the advantages mentioned to effect products that they are used in. Several model cell phones have been released using AMOLED displays (active matrix-OLED) these devices are often lauded for two advantages that come directly from using OLED first the color and contrast advantages and second the power frugality advantage which directly enables longer battery life in the cell phone.
The advantages however must be contrasted with several prominent disadvantages which are really so in a relative sense. The first is the fact that AMOLED displays have variable lifetimes for the polymers used for producing each of the 3 primary colors used to produce usually 16 million colors on the true color displays, the most recently perfected polymers for producing blue light have relatively short life times of only 5 years at 8 hours per day utilization before half light output is reached (see wikipedia link below), though continued refinement of the polymers continues apace and will likely quickly eliminate this issue as a factor in the coming years. The next issue lies in the burn in problem that can occur as the differential light production of the pixel elements increases over time, again so long as development continues to find more robust polymers to produce the primary colors (and it does) the average life time for optimal use of these displays can extend beyond a decade matching or exceeding the life times of previous technologies. Also, this is a user adjustable issue as the color of items displayed can vary battery life, use of dark backgrounds being more power efficient than using light ones for example.
Still the main reason that the producers of these products , Samsung, LG, Mitsubishi being big names so far is that stacking a two layer polymer onto a TFT grid is always going to be cheaper than stacking an LCD above a TFT when both are running on a fab line. The reason is that though the TFT cost is the same between the two, the integration cost between the TFT and the OLED or LCD layers is not. OLED's have already been shown to be able to be deposited spray paint like, though these applications are ideally suited for surface area lighting solutions, it is conceivable that a similar method applied to TFT's in some novel way could lead to extremely easy to produce panels from low to high resolutions. The number of innovations being produced to reduce costs on production is quite high this gives the manufacturers an incentive to get going NOW with ramp up and fab retooling efforts to create more OLED displays over waiting for cheaper production methods to arrive. They know that if they could retool their fabs with the snap of a finger they would immediately reduce costs of production versus producing LCD's and plasma's and they could provide those reduced cost displays for a critical time period at a significant price premium versus a competitor who waits to ramp up OLED displays. Secondly, and possibly even a bigger factor is that not only are the costs of producing the AMOLED displays lower than LCD's of the same size but because of the quality advantages there will be an immediate disadvantage to having production capability for LCD's and plasma ONCE the first large AMOLED displays are available. The difference in quality is so obvious and apparent that consumers will simply see no reason to consider buying LCD's or plasma's. This will allow the manufacturers to ramp down those alternate technologies as fast as possible to ramp up more OLED models thus saving more money. Also great savings will be had in the associated variable supply costs for all the current form factors supported by those display technologies that are produced at different form factors, namely LCD's. An LCD that goes into a cell phone still needs a back light but it can't use the same type of CCFL (cold cathode fluorescent light) bulbs used in a laptop LCD and that is different from the CCFL's used in monitors, the variable procurement costs will be eliminated with OLED which have no such auxiliary product and stocking costs,this will realize a significant reduction in total cost between scaled production of the two technologies for different form factors that again gives the manufacturers a strong incentive to ramp over to OLED as quickly as possible.
Thus I predict that the panel makers are ramping up production to exceed their published OLED production goals as doing so enables them to eek out an advantage both in profits and mind share once the stunning glory of these displays is realized by the masses. Case in point is the fact that Samsung is finalizing a fab that can produce 42" panels, assuming 1 year to operation such a fab would be able to go into mass production on panels up to that size by early 2011, it would literally be an over night appearance of OLED displays at an assortment of sizes which makes sense given the major advantage the first producer out the gate is likely to garner.