Yeah, but keep in mind, TVs are being bought throughout the world and as prices come down, the HDTV-market will expand greatly. Denying this would be foolish. The difference between a normal TV and a Plasma HDTV are quite big, so there\'s all the more reason to upgrade once the prices come down.
Also, you\'re bringing hardware into this, hardware which is not upgradable. Do you honestly think that Sony will force something up on us that doesn\'t work or seriously limited? While photoediting might be a problem because of RAM, movie editing should be all the better once there\'s a certain amount of RAM on the system. You probably haven\'t heard of this yet, but there\'s some really cool things being developed for PS2 already. Software that lets you connect your videocam to the PS2 and stream over while filming. Further, you can do editing on the fly, adding various effects in realtime to your video your filming - effects that are pretty amazing to say the least. Than you have other software that will let you connect cellphones and just about any other electronic devices. It\'s coming and you can bet that the next console (or more precise word "home entertainment system") from Sony will even make this more attractive than it\'s about to become.
What also needs to be said, is that I don\'t think we\'ll have a fullblown PC in our TV for some time - but it will be close enough for the average consumer to raise their eyebrow and find it cool. Again, I may ask, what does the average consumer do with their PC? Surfing the web, writting emails, some very basic wordprocessing, games here and there and perhaps some photo or videoediting. In the future, you won\'t need an expensive PC for this, nor will you need the newest OS. The reason to upgrade on your PC nowdays is getting smaller by the day and people are already starting to get pissed of having to upgrade their PC in order to run the newer software and for that newer OS. Is it necessary? Hell no and yet so many people are literally forced to upgrade. We\'ve been there with Win95/Win98/ME and soon to be XP. Sales are already suggesting that the market is changing and every Windows OS that has launched in the last few years had sold less than its predecessor. I don\'t think I need to point out how this trend is likely to progress if it\'s not going to change...
Oh and guess what, if people slowly refuse to upgrade every 1 to 2 years, where\'s Microsoft\'s profit heading? Down the drain slowly, that\'s where. A TV/home-entertainment system is likely to be all the more attractive if Sony does it right. Most people already have quite good TV\'s at home and will see little to no reason to invest in a PC that needs to be upgraded (for nothing), is costly, buggy, and a hassle to use.
You did name a few reasons to keep upgrading the OS, although I am convinced that it will take more than a few OS to get to that scenario that you have in mind. The next Microsoft OS is likely to increase just slightly over the previous - progressing quite slow until we get a real good reason to upgrade when a steady version comes out that is actually worth the upgrade. Just look at sales now and over the last few years - I doubt it will go back to what it once was like to upgrade.
Besides, think a few years ahead and imagine what the future will look like. Did you see Demolition Man (or other futuristic movies)? In just about every movie, you have a scenerio presented where there\'s some high definition TV in the living room from which you can control everything: the heating, stereo system, internet, wordprocessing, controlling the fridge, lights - just about anything you can imagine. There\'s no PC - which isn\'t suprising thinking that the TV (in that scenario) advanced so greatly that there is no need for a PC (that a) is costly and b) needs to be upgraded). Of course, that\'s only a scenario, but one that could possibly become reality. Sony\'s making the first steps here and if they do things right, they have the potential to put a serious dent on Microsofts market. Don\'t get me wrong though, I don\'t think anyone of us here is saying that the PC will just die, but simply that the market that is so profitable for Microsoft at the moment could shrink to a state where it just isn\'t as valuable as it once was.