The lock mechanism is controlled by rotating the bolster. The mechanism is entirely different than the one on italian stilletos with rotating guards. The mechanics of the lock have changed several times, mostly becuase it is difficult to make this type of lock work along with assisted opening technology.
The lock will actually serve as a safety and as a locking mechanism. In other words, the bolster hold the blade both open and closed.
To open the knife, you will need to rotate the bolster with your thumb and pull the flipper with your index finger. It is actually a pretty smooth motion, and pretty easy to pick up.
Physically, this knife is the same size and thickness as the Vantage series linerlocks - actually, it should be about .020" thinner.
As for the release date, Buck wants to make sure that this new mechanism is working perfectly before it ships the knives, so the release was scheduled for August. New mechanisms take some time to get right, which is the reason for the later availability date.