Microsoft will be finishing the Windows 8 Beta sometime towards the end of July.
"Microsoft was due to complete a CTP build (Community Technology Preview) version of Windows 8 to show off at it's Worldwide Partner Conference in Los Angeles on July 10-14, however it is believed it is unlikely at this stage that Microsoft will reveal anything more than we've already seen," reports MSWin.
According to reports, they expect Microsoft to begin work on the beta branch of Windows 8 sometime between 14-28 July, and that builds should appear during this time. It appears that in the last two weeks in July 2011, from the 14th to the 28th, Microsoft will shift the focus toward Windows 8 Beta.
And, it would make sense for Microsoft to get the bits ready for it's BUILD conference in September, so that it can be distributed to developers. But if Windows 8 Beta is to be ready in time for BUILD in mid-September, then Microsoft does need to wrap up Milestone 3 and start work on the first public preview soon.
And, Windows 8 will also have built in anti-virus protection under the Windows Defender title, with it appearing in builds above the "8010" number. Reports say that the new version of Windows Defender looks like Microsoft Security Essentials and also offers a very similar feature set.