Yeah to date all we know on STR/DEX is the following (I believe in this order):

Yoshi tells us to hold onto our melee (STR) DPS gear.
Patch includes a full suite of Rogue traits which have DEX on them (but are still in development).
Yoshi tells us he cannot say if they will use STR/DEX.
Yoshi tells us they may still change their mind last minute if it uses STR or DEX.

So it's entirely a 50/50 chance. Gear for both if you have the means and you want to prepare ahead of time.