There are rumors that it might be released during the 1st Qtr of 2018, source:
https://www.reddit.com/r/Bitcoin/comments/7e909x/should_we_expect_antminer_s11_in_the_early_2018/Yet, we can't rely on those as most rumors fail to predict the real outcome. I keep visiting Bitmain site for any news or updates so that I will be included in the list of early birds that will purchase upon its release. Well, my money is sleeping for ages and couldn't purchase an S9 since S11 is coming. I'm just hoping that it will be released sooner than expected.
That "source" doesn't even mention Q1. So those aren't event rumors but rather pure speculation.
There is no way the s-11 shows until someone sells a miner that can do 12th with 950 watts
or 15th with 1100 watts.
This is a very simple economic issue not a gear issue.
Bitmain can sell the s-9 at 700 to 800 plus shipping and turn a profit.
So until a competitor sells a kick ass machine they have zero need to build a more efficient miner then the s-9.
What would a big miner with low power cost buy a 15th at 1200 watts
for 3000 or a 13th at 1400 watts for 1000
they buy the s-9. So basically we just won't see a better miner from bitmain for sale until someone comes out with a really good miner in the 0.06 or 0.07 watt per gh area.