(Apologies up front to any Mormons who may be offended by what I say below. My intent is certainly not to offend, but to offer my views on how there can be a path for LDS homosexuals within LDS theology.)
Religion and religious thought evolves over time. Today, we no longer believe slavery is sanctioned by the Bible, and Mormons believe that race and skin color have nothing to do with one's heritage, ability to achieve certain levels of atonement/salvation, current levels of righteousness, etc, but those issues were seen quite differently in the past.
In the past 10 years, we've seen a sizable movement in understanding on the issue of homosexuals, both in society at large and within LDS thought. Top leaders (perhaps excluding Boyd Packer) have expressed that we don't fully understand homosexuality, but it's likely that some people are born with a different orientation, though that doesn't change the commandments we've been given, etc.
Here's how I think the homosexuality issue could play out over the long term in Mormonism, but it may take multiple decades, and we might not be around to witness it (and hopefully Utah football is still in existence at that point.)
Without a doubt, there would have to be very, very big changes in the Mormon theology for homosexuals to be able to be sealed in a marriage in the temple. The role of gender in LDS theology is central, and procreation within marriage is at the very core of LDS belief.
(Quick sidebar: In talking with a devout Catholic who is pretty discouraged about the situation with very good young men avoiding the Catholic priesthood because of the requirement for celibacy, we both agreed that Mormonism has an enviable ability to evolve and change. I told her to cheer up, that the new Pope has the potential to help the Catholic church make long needed adjustments, and that we may see a Vatican III.)
Anyway, for homosexuals to get to full acceptance within Mormonism, a mostly forgotten point has to be re-visited and changed: Women and the Priesthood. If men and women can both hold priesthood callings and perform priesthood ordinances, then the role of gender is more equalized, and the path toward same gender relationships becomes "within reach".
After some amount of time after that sizable change, it becomes more conceivable that LDS thought could evolve, revelations could be received, etc, to facilitate an equality for homosexuals within LDS theology.
Something like, "we don't fully understand why some couples cannot have children and some do, although we know the Lord loves all his children and wants them to be happy and travel the road to eternal salvation. Accordingly, we have received a revelation that all worthy members are eligible to be sealed to the loved ones of their choice, as revealed and confirmed by the Holy Ghost, and to fully partake in the blessings of the gospel and temple marriage".
Again, my intent is not to be disrespectful of Mormons, or mock or otherwise diminish their beliefs. Completely on the contrary, the LDS lifestyle has much to offer, Mormonism has (arguably) a much more attractive message of hope and redemption, among the Christian religions (specifically, that there is no vicious hell awaiting non-believers).
I'm no prophet, I'm no oracle. I'm just a guy who's seen a lot of life over 5 decades, and as I look back at how things have evolved and changed, I believe there is reason for LDS homosexuals to have hope that things will be seen quite differently in the future, though it may be quite a ways out.
I work with a remarkable young woman from Springville, Utah, who is bi-racial and very, very bright. (She just got a PhD from a joint program in Boston between MIT and Harvard.) She is devout LDS, her father was Nigerian, her mother is of LDS pioneer stock. She told me her father joined the LDS church *before* the 1978 revelation on blacks and the priesthood, and it really didn't bother him. As she got older and asked her dad about how he could join a church that overtly denied him the blessings of the priesthood, he told her "truth is truth, and just because some humans are getting it wrong doesn't dissuade me from following the truth".
Think whatever you want, that was a man who had faith and had hope that some (then) current mistakes would be corrected, and they were. For LDS homosexuals, I think there's reason to hope things will evolve in the future.
(For those who are truly offended by my speculation/hunch, I'm drinking my second cup of coffee as a write, and I haven't paid tithing in decades, so you can easily surmise I don't have the spirit guiding me and I really don't know what I'm talking about, if it helps bring some peace back to a Saturday morning. )