[*Edit: Talk about confusing my points*]
First off let me say I have 512 mb of ram. Second off let me say I play Everquest. Third off let me say I've hit the PHYSICAL BARRIER at which my computer said I ran out of memory and proceeded to close things down for me. And not only that, I can reproduce the effect at will in Everquest.
Yea, Ok lets be fair, Everquest may not be the most memory efficient game, but most arn't. If you are upgrading your machine right now, you should be looking at least 3 steps in front of your own feet, meaning you plan to play games that are better than what you can currently play today. If I know I can just barely play EQ with the clip plane down, graphic models on low, textures on low, sky plane on single instead of double, particle effects on low, and hit a memory barrier. I should know damn well that I will probably want more the next time around.
Now the question is, Will I ever play games such as MMORPGs (Everquest) where the global texture file grows at enormous rates. Most games have a preset number of textures that they try to fit in and at the same time keeping that number within limits by reusing textures. But when you have a game with an everchanging world, where things can zone into your level and introduce more and more textures to a specific zone, you realize that your memory usage will now grow and you will need to accomodate for that. Verant knows this and tries to be strict with what they add to the global textures, but they also want to improve their game (AKA, their can only be so many swords that look like that rusty sword you got from a snake at level 1 before people get sick of seeing it). Back in Quake1, You had to run a command line parameter just to load certain maps because they required 32mb of ram and Quake by default used only 16. So, it is obvious that games are increasing in memory demands, the question is, do you think you plan to play the games that are increasing at the fastest rates (mainly dynamic online worlds)?
My beef is not with people saying 256 ram is enough, because it may be depending on what you do. My beef is with people who say you will never need 512, or it is a waste, or there are no games that will ever use it, blah. They are wrong.
Next system will be 1GB+ and I'm sure I will use it all.