No question it's a bigger jump from Women & the Priesthood to Homosexual Celestial Marriage, and there is no comparable change that big in LDS theological history, but if you look at how much has changed over time in Christian - or even Jewish - theological thought over the centuries, I think it's a gap that can be bridged, but it will certainly take time and evolution in thought, unattainable by the current generation.
The Creation Story, the Great Flood, most of the stuff in Leviticus, are seen quite differently today by many, many people than they have been historically. Nobody is stoned to death, we eat hot dogs without a second thought.
Then when you consider the new gospels being found that were (presumably) thrown out at Nicea, such as the Gospel of Mary Magdalene (which is not at all incompatible with LDS theology, but is completely sacrilegious among other Christians), and the movement on a larger mosaic of evolutionary belief becomes feasible.
IMO, it would be an easier jump within Mormonism to work homosexuals into full equality than it would be for Christians everywhere - LDS included - to accept the main, highly provocative, highly disruptive concept in the Gospel of Judas, ie, that Judas' betrayal of Jesus was a set up, an agreement between the two of them.
A bigger jump in LDS thought would be to consider the Book of Mormon as inspired scripture containing truths and wisdom and not necessarily as literal history, but that gap has been bridged before in the minds of many, in the Great Flood story and the Creation story, in the Theory of Evolution. Does the story of the Stripling Warriors lose it's importance as a lesson if it didn't actually occur?
I think the BOM-as-not-being-actual-history view could become more widely accepted in LDS thought in the future (as it becomes clearer the text doesn't line up with archeological and other scientific evidences), but that would be a massive jump, larger than homosexual marriage, IMO.
If you took any given Mormon from the 1840s and plopped them down in today's Mormon church, they would have a massive, massive paradigm change to navigate. Jesus didn't return by the 1880s, blacks have the priesthood, white people are mixing with blacks in marriage and not getting the death penalty, etc. I see a similar thing among many current LDS who have real difficulty reconciling the early polygamy issues, even when it's coming from a faithful source, such as Bushman.
Who's to say that the paradigms of the future won't be similarly radical, to us?