I believe that the Nicene Creed sets down the basics for what a Christian believes. The early Church established that to fight heresy and I believe that if you agree with every statement of that Creed and do not believe anything that contradicts that Creed, you have Christian beliefs.
Since that is my belief on what constitutes Christian belief, I believe therefore that LDS teaching is not Christian teaching.
My belief is that anyone who believes that Jesus Christ is the Son of God and that he died for our sins is a Christian. I believed that was what made a Christian when I was Catholic. I believe it now.
Even mainstream Christianity can't agree amongst the different sects what makes for a "real Christian" a lot of times.