I think what is lost in the entire "nerfing" argument is not the effect that changing spells has on wizards, game play or balance, but rather what effect it has on the players.
I will agree that most of the changes to the spells will balance the game. I also believe that 3.5 will be more fun for the players of fighters and other warriors, and that in a few months, most of the players of Wizards and Sorcerers will be comfortable with these changes. However, I think what is currently causing some discontent and conflict on the boards are not the changes to the game, but the reaction of some of the posters. Let me elaborate...
If you nerf the caster's spells, you lessen the character to a certain degree. I know when I convert my favorite character, who happens to be a wizard, to 3.5, it will result in lower spell DCs, less spells that I can cast in combat, and less damage I can do with a single spell. While this doesn't ruin my character, or change my desire to play, it does take something away from my character. I understand that it is for the enjoyment of others I may play with, but still, my wizard is losing something.
Now, in order to keep abreast of these changes, I check internet bulletin boards and see people saying things how the changes were put in because my character was broken, or need to taken down a notch, or that I'm an abusive player because I use spells like Haste or Harm, that is going to upset me. I'm going to feel as if some who just won a some kind of debate is taunting me.
I'm not saying posters are being abusive, I'm just asking everyone to look at the other guys perspective. When a spell is changed to make it less powerful, the player whose character uses that spell loses something. I may have missed it, but I have never heard anyone say to someone who was upset about spell-nerfing "hey, I'm sorry your upset, and I understand and appreciate that you're going to be losing some cool abilities, but these changes will make the game more fun for more people in the long run."
In the end, everything goes a lot more smoothly if we try to be nice to each other, and appreciate that even when people do disagree with us, that they still have valid concerns and feelings