Can't we at least try to sit back and enjoy a metagame before speculating what's going to drop in May? I'm much more excited about the metagame that's about to start with (possibly) a few suspects kicked out than a metagame where there may be some defensive powerhouses over two months from now.
I've been playing around with a few less common sets, and so far, the most impressive set I've come across is Choice Specs Venusaur. Specs Venusaur is an amazing poke that can rip holes into teams. It's attacks are just as powerful as a Modest Life Orb Roserade, and everyone remembers what a terror that was. What it trades for speed is excellent bulk to take advantage of Blastoise, Milotic, Lanturn, and fighters and fire off incredibly powerful Sludge Bombs and Leaf Storms. This set has served as an amazing wall breaker, doing a solid 78-93% to the RestTalk Spiritomb sets (and it seems that only 16% of Spiritomb sets are running Calm, with maybe a few Sassy ones). Sludge Bomb has awesome neutral type coverage for its common switch ins except Registeel, OHKOing Arcanine and Moltres with Stealth Rock guaranteed. The best part about this set is the surprise factor. Specially based Venusaur is uncommon, and no one wants to switch in Chansey on a SD or Power Whip.
I've also been having an excellent time with Choice Primeape sets. What separates Primeape from other fighters is the move U-turn. U-turn is excellent paired with Pursuit users to take out Cresselia and ghosts to easily clear a way for Primeape sweeps. Adamant Scarf Ape reaches 433 speed, outrunning Ludicolo and Gorebyss in rain and Modest Scarf PorygonZ, making it an excellent revenge killer. Another thing is free U-turn scouting on Scarf Venusaur leads that want to sleep powder your set up lead (Uxie, Froslass).