The first large (17") consumer OLED displays are going to appear next year (2005), I think it was Samsung that said.
Now, by 2008, OLED displays will certainly have completely replaced LCD for a number of reasons:
1) MUCH lower power draw (No backlight)
2) Thinner (Lighter, no glass backing needed)
3) Cheaper (Printed on a glorified inkjet)
4) Faster response time (Response time measured in nanoseconds, not milliseconds like an LCD. No more motion blur).
Anything I miss? Now, the downside, is lifespan; after a few years they dim and must be replaced. However, considering how cheap they're supposed to be (We're talking manufacturing costs that are probably a few dollars as opposed to hundreds with LCDs), we might see laptops with easily replacable displays, or perhaps desktop displays so cheap as to be disposable (Keep it for 2-3 years, but a new one).
The things are better, thinner, lighter, cheaper, than LCDs. Notebook manufacturers are going to jump on it if only because they're cheaper; if a notebook manufacturer charges the same for a notebook but saves 300$ on the screen, that's 300$ more profit. Or maybe we will see notebook prices drop 300$ to compensate.