Lots of good points from arfster, there.
Another significant change going on at the moment is that entirely new display technologies are coming onto the market. LCOS is a prime example: it's been at the fringes of things for a couple of years, but it wasn't until the launch of the Sony Ruby that it made any serious impact on the market. Now we have the Pearl as well, and affordable LCOS rear-projection devices from both Sony and JVC.
There are other technologies on the way: SED will likely be with us some time in 2008, and should be a real killer in terms of image quality. (Whether they can get the price down enough to make it good value for money is still unknown!). I don't know if OLED displays will ever really make it onto the market, but they might. LCD is also going in some interesting directions: I'm looking forward to seeing LCD with scanning LED backlights, and the whole "High dynamic range" LCD concept is intriguing - they're promising 1,000,000:1 contrast ratios. DLP devices driven with diode-lasers sound rather interesting, too.
I can't help feeling that none of the existing display technologies have
quite made it, yet. LCOS, for example, hasn't quite cracked the colour-and-brightness-uniformity problem (although it's getting there) and can have allignment problems; LCD still suffers from poor blacks, questionable colour accuracy, and (sometimes) motion artefacts; DLP devices (or at least the ones anyone can actually afford) suffer from rainbows; plasma, while not a bad compromise, still can't provide a high enough resolution at a low enough price.
By contrast, something like SED has the potential to finally combine the kind of contrast ratios, response times and colour accuracy one gets from CRT with perfect image geometry and finally produce a display with no signficant downside (except possibly the price

).
As a rule it's not a good idea to say "Oh, I'll wait two years, things will be better by then" because otherwise you never buy anything. But, IMO, with the current lack of HD source material, there's really no compelling reason to upgrade to HD at all just yet. And, display-wise, better is on the way.
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