It's been a while since I blogged about another of my (not so) crazy Microsoft rumors. It's also been a while since I've heard any kind of an update on Windows 8 timing. In that spirit -- here's the latest, plus the ground rules for those weighing how believable this information may or may not be.

As part of my job as a full-time Microsoft watcher, I get a lot of tips about Microsoft from customers, competitors, partners and even some Softies themselves. However, ever since I worked for PCWeek as a reporter close to 20 years ago, I had it drilled into my head that until I could get three independent sources — none of whom was repeating something s/he heard in an echo chamber — to corroborate a tip, I couldn’t run it as a story.

These days, I see lots of single-sourced tips being posted by bloggers and journalists. More than a few of these are based on a single, anonymous source, with no further identification to help readers decide whether a tip is likely to be true or not. No “according to a Microsoft partner who requested anonymity.” No “so says a small-business customer angry over the latest slip-up, who asked not to be identified.” Not even a thinly veiled “according to a person who was not authorized to speak for Company X” (but did so anyway).

This lack of attribution made me crazy -- and gave me a maybe-not-so-crazy idea. A year or so ago, inspired by the “CrazyAppleRumors” folks, I bought the “CrazyMicrosoftRumors” domain name. I'm using it for a series of occasional posts here on “All About Microsoft,” where I’ll take a single-sourced tip that I can’t find two other independent sources to verify and run it as a “rumor.”

I’m not going to do this with just any old tip; I am going to pick and choose ones where I have faith in the tipster’s batting average and/or believe the tip makes a lot of sense. I will clearly label these posts as “(Not so) Crazy Microsoft Rumors,” so readers know exactly what they’re getting.

If you want to send along any rumor candidates, just use the e-mail form at the bottom of my blog. All tips I receive are considered confidential, so don’t worry about including your real name (if you want to do so).

And with that... on to today's tip/rumor.

Last I heard, Microsoft's goal with Windows 8 was to release to manufacturing (RTM) its next Windows release around Q2/Q3 2012, after two beta releases, plus various preview/RC drops. I'd also heard that the plan was to RTM Windows 8 for x86, Windows 8 for ARM/SoC (system on a chip) and Windows 8 Server all at the same time.

I'm now hearing there's a different timetable for Windows 8. I've received new information from a trusted source that Microsoft is actually on track to release to manufacturing all Windows 8 versions by April 2012.

I've also heard from my contact that Microsoft's game plan is to deliver a beta build-- not a pre-beta or preview -- of Windows 8 around the time of the Build conference in mid-September. This allegedly will be the one and only Windows 8 beta, my contact said. In January 2012 or thereabouts, Microsoft will deliver a final Release Candidate (RC) test build of Windows 8, my source said. (I'm now thinking that January release is the one that leaked a while back from Dell.) And the next and final milestone after RC will be RTM.

There are a few things to keep in mind here. So far, the Windows 8 team at Microsoft has said nothing about where it's at on its road to RTM. (Thanks to various leaks, we know they've basically finished the internal Milestone 3 build.) The only thing the Windows 8 leaders have offered, guidance-wise, is that Microsoft expects to deliver the final version of Windows 8 24-36 months after Windows 7. It was never clear whether the Windows brass meant two/three years after Windows 7 RTM'd or shipped, and they never clarified. (Windows 7 RTM'd in July 2009 and "launched" in October 2009.)

We also know from previous Office and Windows disclosure patterns that if/when the team does offer a target delivery date, there will likely be several months of padding built in to make sure there will be no publicly measurable slippage. As a result, I'm betting that summer 2012 RTM target we originally heard about might have included that padding, giving more credence to a real internal April 2012 RTM date.

That's all I know, at this point. April sounds better than July, especially for partners and customers trying to hold out for Microsoft to deliver an operating system that will be optimized touch tablets. And if the April 2012 RTM target turns out to be reality, there will be no question about Microsoft and its OEMs being able to deliver Windows 8 PCs and tablets in time for holiday 2012. Heck, they'll likely be ready for the back-to-school market, as well.

In spite of the ongoing Milestone build leaks, there are still lots of Windows 8 pieces that we know relatively little about. I'm curious what's coming with the next version of Windows Live Essentials and when that "Wave 5" bundle of services will hit. I'm also very interested in what Microsoft has up its sleeve, in terms of changes to Windows Update and new Web services add-ons for Windows 8. And, of course, many of us are very interested in what Microsoft plans to do on application model/developer model front with Windows 8, as well.