I do think it would be of great value for there to be movement in the direction of Orthodox unity. Something like a permanent ‘Diet’, an assembly of clergy with several purposes: cultural exchange, mutual support of oppressed Orthodox Christians around the world, and unanimous consensus opinions (difficult, but not impossible).
Ecumenism with Protestants would be both tricky and limited, however, as it would demand they embrace the unified Orthodox consensus, which few of them would agree to.
With various non-Catholic denominations it varies.
we are closest to those who acknowledge the True presence of Christ in the Eucharist like the Lutherans and to some/more extent with Anglicans and Methodists. At the other extreme, there are groups with next to nothing in common with orthodoxy -- with those we should be united on common purposes like anti-baby killing etc., and be content to agree to disagree.