I think most Christians have an effective disbelief in the Trinity.

It seems to me that the standard, non-theologian Christian doesn't REALLY have faith in the Trinity, but they have no problems saying that Mormons go to hell for questioning Trinitarianism. Most of my Christian friends make big distinctions between Christ and His Father, and won't explain the Trinity in any common terms, for fear of committing some sort of Heresy. It makes sense, because the Bible isn't very clear about the Trinity as it is defined in the Nicene Creed.

I think that the Church has done well to boldly go against Trinitarianism. The early Christians had a big problem of kicking out anyone who questioned their biblical interpretations(ironically, Mormonism now has a similar problem).