Just gonna come out and say that cacnea is a complete MONSTER now. If you can predict at all with sucker punch, cacnea's check list wittles down to something like murkrow and croagunk and to an extent bulky mienfoo (and perhaps the odd houndour). It just smashes so freaking much and can still set up on a reasonable amount of stuff like staryu, ferroseed, hippopotas etc..
Drilbur, while frowned upon, is really great this metagame as prem said. I wouldn't say he's as good a sweeper as he is a revenge killer, though, as he struggles to switch in safely and doesn't hit hard enough without a life orb and still dies to priority in every form if he does finally manage to set up. But when used as a revenge-killer, nearly nothing escapes his twin claws of mass destruction.
Your points here coincide more than you might think they do. Frankly, sand teams simply love something that can take water-types, and Cacnea undeniably does this to a fantastic extent. In all honesty, I think the stigma possessed by the people who played two metagames or so is gone; I haven't had to run Bronzor to deal with Drilbur yet. It's at a good usage right now, one where it is merited enough to be used (but not always the greatest Poke to use, since opposing Snover smashes sand so hard and Snover's on the rise). It also has enough variation in sets to make it somewhat a surprise to deal with every time; I wouldn't deem it broken though (I've been flaunting max Defense Mienfoo, which is typically a pretty good check to Swords Danceless versions, while most teams shouldn't let it get an SD anyways).
I'd say Murkrow's probably the most threatening poke this gen, purely because it can hit hard straight away with 19 speed and many pokes are scared of switching in because it has really good coverage. It's far from broken though as stealth rock, life orb and brave bird kill it off really quickly.
Murkrow's definitely a big threat right now, and I would agree that HP Grass in slot 4 is just ridiculously fun. I think it does have a pretty broad set of counters, however, including Chinchou (LO Brave Bird and HP Grass's damage outputs are typically comparable), Aron (uncommon but what are you going to do to it), along with some checks, such as defensive Staryu. Definitely a fun Pokemon I've been using lately, and if you can keep up hazards and get rid of Staryu, then things get even more fun.
Speaking of the ubiquity of Staryu and Chinchou, I've had some fun with Agility Chinchou since it takes advantage of bulky Water-types so well. With HP Fire it's a monster late game, with HP Grass it's basically the perfect Staryu / Chinchou core solution.
I'm not sure if it's just on PS!, but Abra is really good
I've been seeing more of Abra lately, especially with Charge Beam which makes it, as prem said, essentially the best Murkrow lure. I remember something similar happened a few metas ago, however, where people will simply afraid to use Abra; in reality, it's a pretty safe Pokemon, especially with Magic Guard ensuring that you could get a late game revenge kill against a set up sweeper if need be as you essentially live any attack.
In terms of other discussion, I'd like more on Scraggy. How many counters per team are you seeing? Which counters are you using? What spreads on Mienfoo do you find best? Is Croagunk even worth it anymore?