A couple of useful Blue replies in the same thread, confirming that Season Two should be months shorter than Season One, and that the three new sets coming in Patch 2.2.0 are not planned to be Seasonal legendary items. Blizzard on Season 3 Length and New Item Sets:
Tyvalir: We don’t have plans right now to make the three new Sets (Delsere’s Magnum Opus, Wrath of the Wastes, and Unhallowed Essence) coming in patch 2.2.0 exclusive to Season 3. That said, we’re still determining which of the new Legendary items will be Seasonal to start.
Assuming the above is still the case when patch 2.2.0 goes live (which we’re aiming to do between Season 2 and Season 3), then you’ll be able to find the new Set items regardless of whether you’re playing a Seasonal character.
I was getting so hyped reading this preview… Then I see this and other blue posts like it about how this isn’t happening until, at the very least, this season that just began a few days ago ends. So 5+ months from now.
Tyvalir: We mentioned during our recent Tavern Talk that we’d like for Season 2 to be shorter than our inaugural Season, and Nevalistis confirmed our intent here as well as on Reddit Diablo. You’ll definitely have a shorter wait this time before the Season ends.
On the plus side, you’ll have the advantage of being able to dig into what’s included in patch 2.2.0 on the PTR, figure out what you like (and don’t), and determine what build and gear you’ll be running once Season 3 starts. When it does, you’ll already have a mental list of what gear you need, and be ahead of the game fresh out of the gate.
Just my .02. Hope it helps, Hartagon!
If you’ve already blocked it from your memory, Season One began 29 August, 2014 and ran until February 3, 2015. That’s 158 days, or just over five months. From what the devs have said lately, it seems like 3-4 months is more their target duration, assuming the new Patch content is ready to roll by then. And I guess the PTR will inform us about that soon enough?