Whether or not they'll win is another matter. Sexual Orientation has yet to be really clearly defined in regards to its tier, and that's what most people are arguing is being discriminated against. I take a different tact, feeling it is GENDER that is being discriminated against, and gender HAS been proven to be under the EPC and of a higher standard than the lowest tier (though also not to the level of race).
In regards to removing itself, I agree with you completely.The current argument is based on what benefits the government will bestow upon a couple that chooses to allow the government to "bless" their union. Government should remove itself from marriage in every way. Anything else discriminates against someone.