Wargaming said that this couldn’t be helped: “World of Warships wasn’t initially designed as a cross-platform project. That means that if you’ve played the game already you would want to keep using the original client. If you log in using Steam, you automatically create a new game account, which binds to your Steam account.”
Other than that, it sounds like full steam ahead for this client. The Steam and Wargaming versions will use the same servers and the same version of the game, allowing for even more hectic battles on the high seas. The team posted a FAQ on Steam to address some of the details of the coming launch.