That's always the scary question of buying into a "new" technology. You go out and spend $2000 on a new TV and capable home theatre system only to find out that 3 months later something bigger and better has made your system obsolete. Well what about Blu-Ray games and movies? Is something called "Diamond-Ray" going to appear and change it all again? The answer is... No, Blu-Ray is here and nothing is going to take it away. I have two solid reasons and multiple supporting points for each. I'm warning you that I rant and I'm proud of it!
The first reason is that Blu-Ray supports our current high definition standard. All of our top of the line TV's (and the ones being released in the next several years) are not supporting any more than 1920x1080P resolution. If I've just lost you with that statement then please take a quick look at this article for an explanation. 1080P has been adapted by all Blu-Ray movie companies, TV and home theatre manufactures, TV networks and satellite/cable companies. To force all of those 1080P sources to switch to something else would take several years alone. The other consideration is that the movies could become so long and detailed that even a dual-layer Blu-Ray disc won't be big enough to hold it. Even though the two standard sizes of Blu-Ray disks are 25GB and 50GB, the maximum size is said to be 200GB. I'm sure if the movies start getting bigger, they will just use higher capacity discs.
The second reason is that Blu-Ray is cheap to produce and looks nice on display. The most likely competition for Blu-Ray is not a new type of technology standard but a new method of media distribution. We are going to see several attempts at new media and online streaming and they will fail for simple reasons...
USB Flash Memory - You know those "thumb drives" or "USB sticks" that can hold tons of pictures and files? Well I've heard that they might put high definition content on them and sell them as competition to Blu-Rays. First of all they cost too much. A 50GB USB stick is going to run you $80-90, and that is without the high budget movie on it. A Blu-Ray costs about $3.50 (average based on bulk) to manufacture. If a magical event happens where the price of 50GB USB sticks drop that low, Blu-Ray will just go cheaper. I could also mention that their is no reliable security application for USB sticks, and I know that the companies won't want people having easy copy/paste options with their movies.
Online Streaming - Several major companies (Disney, Sony, Panasonic, Lionsgate, Samsung etc.) have all expressed interest in developing internet based streaming of movies. They want to setup a system where you have an account, buy the movie and then have unlimited "Access" to the movie without actually being able to store the movie on your own computer or drive. Whenever you want to watch it, you just stream it from their servers. Sounds like a high definition version of Youtube. However it will fail and I will tell you why. You may not know it but you likely have a limit set on how much you are allowed to download every month. On my Shaw Cable internet connection I am allowed to download 60GB a month. Well the question here is how many movies do you watch a month? I would say I watch 3-5 movies a week, and we'll say 16 a month. That's 16 high definition movies at 30GB each, 480GB total. Is Shaw Cable going to up my limit to 480GB a month? Hell no! The costs for them to allow that to everyone would be astronomical. If you only watch 2-3 movies a month and don't download anything else (games, pictures or porn) then maybe this streaming system will work for you. I could mention that if your connection speed sucks, then the movies will pause to buffer or just skip, which just adds to the poorness of the whole idea. To make it even worse they plan to make us pay for the movies without any physical keepsake. I don't know about you but I like to show off my movie collection. I like the cases and the little books they come with. I don't buy many movies but I sure like the ones I have. They would have to drop the price significantly before I would sacrifice my movie shelf.
The bottom line is that DVD was the top of the line of the "Low Definition Era" (1940's-2006ish) and now that the "High Definition Era" is here Blu-Ray is the best format for what the standard offers. Several other distributions will occur, and may be acceptable for few but at a sacrifice that just isn't worth it. I would predict that the "Extreme Definition Era" will not begin until 2016 at the earliest.