I'm going with silenced and VBD on this one. People look at mega Gallade and say: shit ability, garbage. This thing is not to be fucked with. It sits at 366 attack uninvested. You could technically run max speed, max hp, bulk up + 3 attacks. Bring it in safely, which shouldn't be too hard, click bulk up and then even Crobat can't possibly take it out with brave bird anymore unless it's banded. I 100% see this going BL, especially considering the other stuff that has already been banned from UU. Swampert, Metagross and possibly Altaria will quickly join Gallade as well. I can see mega Sableye sticking around for a bit, but to be completely honest, I think it will end up in BL as well.
As far as the others go, Camerupt looks like fun, even though I ran some calcs and Sheer Force boosted attacks really aren't THAT overwhelmingly powerful. It might get some use in UU, but not even as much as Mega Abomasnow, which has a boosting move + priority to make up for it's speed. Mega Sharpedo will definitely be a top tier threat. 70/70/65 defenses still aren't fantastic, but the combination of speed boost pre-mega with base 105 speed means it doesn't even have to run max speed if combined with protect. Add some hp ev's, substract LO recoil because there won't be any, and it could actually live most priority in the tier bar mach punches. I don't really see much hope for Glalie/Steelix/Audino to have a metagame defining presence. Pidgeot as a fun defogger with decent offensive pressure doesn't look all too bad. Mega Sceptile though, the SD set is for sure going to have merit, considering something like SD Virizion already puts in a lot of work in the tier as it is (not a fantastic comparison, i know, but let me be excited). Finally, Lopunny will probably be my most used mega simply because I love fighting types, and I completely agree with RowDog that it shouldn't be underestimated :].