I think both companies are going to release them towards the end of the year. Samsung has been talking about theirs not being ready possibly until 2019. Only the latter will be a smartphone though.
I don't know which one will be released first, but I know which one will be abandoned first.
So sad as I sit hear listening to Cortana on my Invoke. I feel like the family in the movie A.I. Artificial Intelligence when they know they'll abandon their robot, son, Haley Joel Osment.