Update time
Whimsicott: Unranked ---> D
Mienshao: Unranked ---> C
Jellicent: Unranked ---> D
Cresselia: C+ ---> B-
Slowbro: A- ---> A
Gastrodon: C- ---> C
Hydreigon: C+ ---> C
Thundurus-T: C+ ---> C
Manaphy: B+ ---> A-
Mega Aerodactyl: B+ ---> A-
Mega Alakazam: B+ ---> A-
Umbreon: C- ---> D
Hawlucha: B- ---> B
Chansey: Stays in A-
Skarmory: Stays in A-
Crawdaunt: Stays in C+
I will explain only the changes that not everyone agreed about or didn't get much discussion.
Jellicent was added to D rank because it has a niche as a spinblocker on Spikes stacking defensive teams and a reliable counter to Keldeo. However, it has a ton of flaws, such as huge Pursuit weakness, mediocre bulk, weakness to many common threats, and competition with other bulky Water-types, which is why it didn't go any higher.
Manaphy was moved to A- because its TG + RD set is very effective atm, being able to shred stall teams to pieces and annoy the fuck out of sand teams, removing their sand and threatening everything they commonly carry outside of Ferrothorn, which is easily trapped and KOed by Magnezone. In general because Manaphy's usage dropped over the last months, people have stopped preparing for it, which made it more effective. Even a simple TG + Wacan Berry can often get 2 KOes against bulky offensive teams.
Chansey stayed in A- because it's superior to the rest of the defensive Pokemon found in B+, such as Alomomola, Mandibuzz, and Quagsire, because it handles a much bigger array of threats. Yes it's passive, but so are Quagsire and Alomomola to a degree. Of course one could argue that Quagsire and Alomomola should be dropped to B rank, which is definitely a possibility, but before this happens i can't see those Pokemon in the same rank as Chansey.
Skarmory also stayed in A- because people seem to think that it is useless with Magnezone getting so popular, instead of just equipping it with Shed Shell. Skarmory still handles many threatening offensive Pokemon, such as Excadrill, Dragonite, Landorus-T, Mega Gyarados, Mega Pinsir, Mamoswine, Diggersby, Mega Tyranitar, and Mega Scizor, and unlike Chansey it's a much better team player and is less passive, thanks to access to Defog, Spikes, and Whirlwind, all of which Chansey lacks. Spikes are often overlooked but they have started becoming a very useful option on defensive teams, allowing them to better combat opposing stall teams and put more pressure on offensive teams, instead of just playing passive all the time. Even though Skarmory doesn't wall that much atm and is easy to trap and KO with Magnezone, it makes up for it with its ability to support its team, and Magnezone can be dealt with by Shed Shell, as long as you are careful and don't bring it mindlessly into Knock Off users.
Umbreon dropped because with Aegislash gone it lost the biggest reason to use it. I may remove it completely from the list in the future but i first want to see what you guys think.
And that's it... I don't really have anything specific in mind for you guys to talk about and the list seems pretty solid in general, so just talk about whatever you want.
EDIT: Didn't see Jukain's post, seems like a good few nominations for discussion.