For those that are not familiar with Zion's Camp, feel free to read up on it on Wikipedia. To give a brief synopsis, the Mormons were driven from Missouri and forced to abandon their property; Joseph Smith received a revelation that they needed to go back and fight for it; a group of 200 members (mostly men) followed Joseph Smith back to fight; after much tribulation, a couple of miracles, and a long trek back to Jackson County, Joseph Smith received a revelation that they were to head back to Ohio without redeeming Zion. Many of the members were upset and lost faith, but many of those that remained faithful became leaders in the LDS Church. Today this story is shared as a faith-promoting story about following the prophet no matter what.
Many of those who went on Zion's Camp went back to Ohio discouraged, confused, and upset that the Lord's will did not prevail, but at last they were willing to follow the prophet. The whole thing was just a big test. Back then, the Latter-day Saints failed to regain Zion. Today, Latter-day Saints failed to stop the sea of monogamous gays from obtaining equal protection under the law and raising their families in safety and protection.
Just wait, I promise you that you will hear gay marriage being compared to Zion's Camp in a few years from now. Either Prop 8 will be overturned by the Supreme Court, DOMA will be overturned, or Californians will vote to grant equal marriage rights, but no matter what, I don't think anybody doubts the eventual outcome. And Mormons will be left wondering, why? Well, you heard it here first. It was all God's will. Just a big test for the Mormons.
On a side note, it seems like most believe that the California Supreme Court will uphold Prop 8. If they do, I promise you that Mormons will be done funding the fight against gays and equality will prevail in time. I cannot stop thinking about the middle class LDS family in Sacramento that was interviewed by the Sacramento Bee because they had donated $50K to the Yes on 8 campaign. I am sure they will become another piece of Mormon folklore about how blessed they were, and I am sure that someday Mormons will be talking about the horrible death that gay rights activists died for going against the Saints. Hell, I may even write a book about it.