The creators of the show seem very down-to-earth about the whole thing (Kim Manners, major producer & director, is the one who gave J&J the wincest in the first place!), and i think they're smart enough realise that cutting out the fraternal connection would utterly destroy the show. And it's the fraternal connection that the slashers play off *g*

I think that overall SPN's production is coming already from a slightly more grassroots, fannish base than SG1, so I have a bit more hope for the creators!