I think it's pretty clear that the endgame should be that Gaia can run in other browsers when they're ready. The ideal situation would be that the platform is

I think it's pretty clear that the endgame should be that Gaia can run in other browsers when they're ready. The ideal situation would be that the platform is developed and standardized enough that you can swap out the middle layer without any problems, even in complex apps like Gaia. But it would be a bit silly for Mozilla to pursue that at the cost of an expedient release of FF OS, when there aren't even any other implementations to test with. :)