I'm part of the "Vanguard Agaisnt Psionics in Fantasy" ideal.
It just doesn't feel right for the genre; wizards and sorcerers manipulate arcane energy, using the very essence of the world around them through rote ritual or birthright.
Psions bend reality with their will, bringing into being what their minds allow.
For some, this is the same thing. For me, it isn't. I'm also not too fond of magic in modern settings and post-modern settings; I like my fantasy to have wizards, and my tech-age or cybertech to have psions.
Beyond that, I never played 1E, but I did play 2E, and psionics there made me want to gag. When I heard that 3E was doing psionics, I was skeptical, but I did pick it up... and I was disappointed. In a campaign where psions were the only option, maybe I would be comfortable -- like a windswept far-away world where psions were the only "mystical" class (no wizards or sorcerers), but with 3E magical/psionic transparency, weak (IMO) attack and defense modes, and the feeling that psionics was just "tacked-on," so to speak, at the last minute by Wizards, I think that they should just leave it as a supplemental rule set, and think about revising it at a later date.