Info about 1.18... When?

[Betelgeuzah]

Go look at previous Letters from Yoshida, I believe it was around producers letter 3-5 he stated this. He said the Combat changes would be split over 2 patches (1.17 and 1.18) and at the conclusion of the last patch we would also be introduced to our first Endgame Dungeon.

That's not exactly accurate.

Yoshida: In the spring you'll be getting that high-end dungeon and the first round of battle changes. Not everything, but the first round.

The rounds come in two-month intervals, as said in the aforementioned interview, so everything points towards 1.18 having the first round and the second round being released sometime during the Summer.