Hah, I keep forgetting Mega-Gardevoir exists, I've still never fought one so I don't really know what they can do... Yeah, she could be even more threatening.
To be honest Sableye already needs a lot of prediction and mindgames, so I think it's fitting they've found a way to keep it's character intact. It could well be the number 1 stall Mega, and it could be a decent bulky Calm Mind, but it's a mega that's going to need a team built around it rather than the slap-on and done styles like kanga and marwile. I kinda like it more like that, it looks like it could be really useful (if the stats are right), but doesn't look like it'll feel cheap to use. I guess it depends on what his Special is, as if that's high enough he might be quite capable to dishing out damage without status (if not Gliscor will also poop all over him)... either way I think Will-O will be more common than Toxic personally, but I guess we'll see.
And gah, I hate Mega-Banette! Don't say that name around me....
It probably doesn't help that in my tabletop adventures game we gave Banette an amazing ability which reversed (and halfed for balance reasons) the effects of all healing and draining on the battle field while he was out (ie. Lefties, Recover, Drain Punch [and most dangerously stuff that could do 66% heals (and thus 33% damage in cursed room) like sun boosted Moonlight, new moves like Dynamotor [on third and subsequent consecutive uses], and edited moves like Heal Order [on first use, consecutively weaker], and the draining effect of the new move Needle Spikes] all hurt the user, while Life Orb and Curse healed; Statuses, Recoil and Attacks where counted as damage and not effected). I knew full well nothing would be as cool, and arguably broken, as that, but anything less won't impress me after the fact.