Meaning for Isaiah's audience: The Lord announces his coming. This particular arrival is not made distinct in time, and may be seen as referring to both Christ's mission and to the final judgement.
The verse ends with the wider extent of the lands recognizing the Lord, and awaiting his arrival. This ties best to the plural concept of peoples in that the law is spread to distant locations, and those locations trust on the Lord.
Meaning for Jacob's audience: In addition to the general meaning of the verse, we have once again the reference to the "isles" that Nephi has so clearly associated with their own location. Much more than for Israel, this verse would have personal meaning for the Nephites, a sign of their inclusion in the blessings of Israel, for they are on an isle, and the "isles shall wait upon me, and on mine arm shall they trust."