From Extreme Tech:
Spoiler :We're interested to see what else 2K Games will do with Civilization V between now and the final launch, currently rumored to be in late September or early October. Our contact at 2K tells us that the technology tree is still being tweaked and polisheda nice move, as that's crucial to the balance of any Civilization game. And the multiplayer and mod functions are important components that will define the experience for many players.
I wouldn't put much value to statements of someone whose "contact at 2K" apparently didn't tell him the exact release date for the game even though it has been known for 2 months. Or someone who apparently couldn't be bothered to recheck their boilerplate review from half a year ago.