http://us.battle.net/hearthstone/en/blog/20475356
Summary:
New Standard year is the Year of the Mammoth.
Azure Drake, Sylvanas, Ragnaros the Firelord, Power Overwhelming, Ice Lance and Conceal are rotating out of Standard and the Core Set. To compensate players, you will be paid the full dust value of the cards AND also get to keep them, unlike when a card is nerfed.
The plan is for three large expansions this year. Adventures are sort of dead. Instead they will release free single-player content alongside new expansions, or something to that effect. This won't happen with the Spring 2017 expansion, but will happen with the middle 2017 expansion.
They want to promote Wild more now that it has a shit ton of sets in it.
New Rogue hero that you get for winning 10 games in Standard after the Spring 2017 set comes out.
Before the Spring 2017 expansion launches they are doing daily login rewards where you get random free shit.
Thoughts:
The nerfs are whatever. It shows that they absolutely hate the idea of combo decks in Standard, which we knew already, but kneecapping decks like Freeze Mage which were already going to be crippled by the rotation of Emperor Thaurissan seems wrongheaded. Don't be fooled by any pronouncements about how they want to increase design space with these removals - they said the same thing about nerfing Blade Flurry and then didn't print a new rogue weapon for a year. This is strictly about taking options off the board.
Printing more cards a year is good, even if it means I no longer get easy access to key cards from adventures. More cards = more shakeups to the game, more chances for the devs to fix their mistakes naturally instead of with the nerfbat, etc. Same for the free shit.
Nobody is going to play Wild.