It seems that Apple may launch next version of Mac OS x, Mountain Lion on July 25. 9to5mac is reporting that Apple stores are planning for overnights on July 24 which indicates that customers might get something new next morning.
In this overnight they could update all Macs to Mountain Lion. It seems that Apple is going to repeat last year as they had announce OS X just a day after announcing there quarterly result and this year same is going to happen as on 24 July Apple is going to announce they Quarterly results.
Mac OS X Mountain Lion will bring over 200 changes like better integration of OS X with iOS, Dictations, iCloud, better integration of Facebook and Twitter and so on. Apple has already announced that Mountain Lion will be available on July. Users can get OS X Mountain Lion from Mac App Store for $19.99 on the day of launch