Blizzard has released a great preview video of the upcoming 'Anniversary' patch, v2.4.3. Players will be able to take part in the special month-long anniversary content that is a nod back to the original game in the series. In addition, several of legendary items have been updated, both general legendaries and those part of class sets.
Players can also look forward to:
Greater Rift reviesions - monster distribution has been altered to spread them out more evenly, floor sizes are roughly equal to one another, tilesets should be more randomly deployed, and an additional chance at a Legendary Gem upgrade will be granted to players who do not die clearing GRs
Quality of Life changes that include:
leaping critters can be killed in mid-air
unattackable foes (burrowed monsters, etc.) will spend less time in that state and more in the fight
updates to shielding, reflected damage and electrified
monsters immune to CC will be slower than normal
Myriam the Mystic now features the ability to dye player gear