For some reason, Isaiah 10 and 11. It's an eschatological vision of world peace and the restoration of the Davidic monarchy. It's eschatological and very pastoral. I suspect that it was chosen because otherwise the Haftarah of the 8th day of Pesach in Chutz La-aretz would be completely neglected, but I can't help but think that the connection of an independent State of Israel and a Messianic vision was very purposeful.
As I've mentioned, I'm not entirely comfortable with the conclusion that the value of the State is entirely dependent upon it being the beginning of the Messianic process.
If it were up to me, I'd choose Isaiah chapter 53 as the Haftarah of Yom Ha'atzma'ut. It speaks of God's long suffering servant - a metaphor for the Nation of Israel - finally getting his just rewards. His persecutors recognize their folly, though he never acted to try to impress them in the first place. It's a very moving section. It'll also be interesting to reclaim that chapter - known for its Christological interpretations - and apply it to something as Jewish as the Modern State of Israel. But really mostly because it's such a beautiful and stirring piece.
Alternatively - Ezekiel's valley of the dry bones.
But I'm not into 'od ha-yom be-nov' for Yom Ha-atzma'ut. Just don't like the implications.