When I first told my wife a few years ago that I was starting to doubt the claims of the LDS church (and my belief in God, for that matter), she was understandably freaked out. Thankfully, we gave each other time and space to deal with what was happening, and our relationship now is better than ever.
But one question she asked me every so often during those first few months was, "Have you reached a conclusion yet?" The implication was that I was going to reach a final conclusion that the LDS gospel was "true" or "false".
It was a little frustrating to answer such a question, because my answer was, and still is, "yes and no". Yes, I have reached a conclusion. My conclusion is: No, I may never reach a conclusion. And that's okay. I no longer subscribe to the concept of reaching a final conclusion that cannot be changed by further evidence. I now regard all conclusions as tentative (yes, even this one!) and contingent on being supported by good evidence.
The false dichotomy that the LDS church is either wholly true or wholly false is often emphasized by church leaders. For example, Gordon B. Hinckley gave a General Conference talk in April 2003, in which he boldly stated, "Either the Church is true, or it is a fraud. There is no middle ground. It is the Church and kingdom of God, or it is nothing."
This is obviously oversimplified. It is a fact that there are many positive things about the church, many true principles taught by it, and many good people who believe in it. However, it is also evident that Joseph Smith's foundational mythology includes many claims that are... shall we say, not entirely grounded in reality. Must we conclude that Joseph Smith was either the Prophet of God on the earth, or else a willful liar and a fraud? No. I don't believe the evidence completely supports either claim. Life is much more complicated than that.
Someone on a discussion board recently asked, "What would it take for you to believe again?" For me, that question is kind of like asking, "What would it take for me to believe the earth is flat?" It would take a whole heck of a lot of observational evidence, as well as a coherent, parsimonious explanation for all the other evidence that seemed to indicate that the earth is a spheroid. The same is true of belief in the LDS church. In principle, I suppose the dead could start walking the earth, testifying of Joseph Smith and the restoration. That would challenge both my naturalistic worldview and my view of the LDS church. In practice, the possibility seems so unlikely as to be ignored.
To summarize: Yes, I hold certain tentative conclusions with an estimated probability, given the evidence I know about. I may believe the likelihood of the existence of gods is very small, and I may believe the likelihood of the LDS church being a true church (whatever that means) is even smaller. However, given enough good evidence, I am willing to change my mind. So, have I reached a conclusion yet? Yes... and no.