Ok time do some nominations (if these have already been nominated, no problem, just read my explanation):
Hustle to B tier
Hustle is a very good ability. It has the potential to make anything with 60 Base Attack or more a physical juggernaut. Hell even Togekiss can go physical with only 50 Base Attack. The accuracy drop is of 'course unfortunate, but most of the times it is worth it. Ask Durant... Also with the introduction of Hone Claws, many pokes could get the equvalent of a 2.25x boost to their attack after just one HC, in combination with Hustle.
Insomnia and Vital Spirit to B tier
We all know how deadly the sleep condition has became in BW. When one poke is asleep, it is as good as dead, most of the times. And it isn't like we don't have many viable Sleep inducers in our meta. Breloom, Roserade, Tangrowth, Venusaur, Smeargle and even Politoed all use sleeping moves. Being able to block sleep, instead of needing to waste 1 of your pokes is very useful and thus Insomnia deserves the B tier status.
Shield Dust to A tier
What the fuck is this wonderfull ability doing down here? As many others have mentioned, Shield Dust is the best anit-hax ability. And we have lots of hax in our meta, such as Scald, Jirachi, Waterfall flinches, Def drops from that damn Ttar, SpD drops from that damn Gengar and the list goes on. Many pokes would love this ability for the ability to completely shut down Jirachi and Scald users, such as Ferrothorn, Haxorus, Lati@s, and Virizion.
Snow Cloak to B tier
Just for the sake of consistence, as Sand Veil is in tier B also.
Unburden to B tier
Unburden is a very useful ability, that fits like a glove to many sweepers. Which sweeper wouldn't love a free Agility boost, when using an elemental Gem. Imagine freaking Terrakion with it! It would be absolutely fucking broken! Or Gliscor and Tornadus... And now that the pinch berries are confirmed to be in B2W2, the ability gets even better. On a good day, this ability good even be low A-tier, but for now B-tier is a must. The only reason it is not sure A-tier is because it is a one time use ability, which is somewhat limiting. (Imagine a physically strong Flying/Fighting poke with a moveset of Acrobatics / Close Combat / Swords Dance / Recycle, holding a Flying Gem and having Unburden!!!)
Suction Cups to B tier
Being immune to phazing is nice! I mean really nice! If more viable pokes had this move, we could as well be proposing a Baton Pass ban, since many Baton Pass teams would become unbreakable without being able to phaze its members, not even with D-Tail. Also many bulky boosters would become really difficult to deal with, since you wound't be able to phaze them anymore. Imagine for example Bulk Up / Sub / EQ / SE Landorus with Suction Cups and Leftovers. Skarmory comes in to wall you? No big deal he can't do anything, since it can't damage you nor phaze you.
Wonder Skin to B tier
Many walls and sweepers would love the ability to evade status moves, Taunt and phazing. You thought that a 75% chance to stop a physical sweeper was unreliable (WoW)? Let's see you using the same move with 50% accuracy... Many physical attackers that can 2hko Skarmory at +2 (Haxorus and SD Landorus in sand) would also love the ability since they would be able to beat their best counter 50% of the time. Many slow stat-uppers or hazard layers would adore the ability to dodge a faster Taunt 50% of the time.
Harvest, No Guard, Compound Eyes, and Multitype(know Typing) will be moved to A tier While Multitype (Do Not know Typing will be moved to S Tier. The Next Phase is C Tier Nomination and Discussion. This phase will last five days. Bold Your Nominations and have fun!
While you have moved most of these abilities, you haven't deleted them from the B tier. Also Multitype (know typing) is still in B tier, while it should be in A tier.