We’re now hearing some new rumors that are citing completely different dates from what we’ve heard in the past. These are the first set of rumors to not agree with the previous roadmaps leaked, including various reputable sources.

According to Businessweek’s sources, public testing of the next Windows will begin at the end of the year. As well, we will not be seeing a tablet until around June 2012:

Microsoft Corp., the world’s largest software maker, won’t release a competitor to Apple Inc. and Google Inc.’s tablet operating systems until the 2012 back-to- school season, people with knowledge of the plans said.

Public testing of a new version of Windows will begin at the end of this year with partners and customers, said the people, who declined to be identified because the plans haven’t been disclosed publicly.

Businessweek: Windows 8 Beta in Q4 2011, no Windows 8 tablets until June 2012 | Windows 8 Center

Thanks for the news JMH
I do hope the the sources of this news are wrong. I prefer to think that M3 leaks will start soon. And that a Beta will be available by summertime.