In the keynote at WWDC we saw all first hand details of the next major version of OS X : Mountain Lion. However, like last release, Tim Cook and company were left the stage without announcing the release date.
Well, according to some reports (source) July 19th is the most possible date for Mountain Lion release, which is a day short of a year after its predecessor, which was launched on July 20.
What we know is that when Apple says “in July” I would see firing of its launch in the early days of the month. Remember that update will be only available through the Mac App Store and we will watch to warn you as soon as available.