“Looking into its crystal ball, Gartner Group has predicted that Google’s Android will become the second largest smartphone platform by 2012,” writes Daniel Eran Dilger in the one-man blog he grandly calls Roughly Drafted Magazine. “Problem is, nobody’s talking about how terrible Gartner is at predicting things, or that Gartner’s ‘research’ has historically been paid for by special interests.”

So begins Dilger’s reaction to an interview with Gartner analyst Ken Dulaney that appeared Tuesday in Computerworld and was picked up uncritically by more than half a dozen tech websites.

Drawing on historical records and making generous use of internal Microsoft documents made public during antitrust proceedings, Dilger attacks not only Dulaney’s numbers, but the credibility of the entire Gartner research group.

The result is a 1,700-word screed that may be the most thorough take-down of a tech industry analyst — and his employer — since Eliot Spitzer went after Henry Blodget.

At issue is Dulaney’s forecast that has the major smartphone operating systems divvying up the 2012 market as follows:

• Nokia’s (NOK) Symbian: 203 million devices (39% market share)
• Google’s (GOOG) Android: 76 million (14.5%)
• Apple’s (AAPL) iPhone: 71.5 million (13.7%)
• Microsoft’s (MSFT) Windows Mobile: 66.8 million (12.8%)
• Research in Motion (RIMM) BlackBerry: 65.25 million (12.58%)
• Miscellaneous Linux devices: 28 million (5.4%)
• Palm’s (PALM) WebOS: 11 million (2.1%)

Dilger finds it hard to believe that Android market share will grow 400% while the iPhone’s stands still, but he is hardly a disinterested observer. He pens a pseudonymous column for AppleInsider and has written a book about Mac OS X Snow Leopard to be published next month by Wiley. His blood runs Apple red.

But he knows his stuff, and he has mined those Microsoft documents for some pure gold. He points to evidence, for example, that Microsoft paid Gartner — along with IDC and Forrester — to tilt results and publish reports putting Microsoft products in a favorable light.

One document, according to Dilger, shows that Microsoft spent hundreds of thousands of dollars in an effort that “successfully lobbied and changed the Gartner Group TCO [Total Cost of Ownership] model to show Windows as providing the lowest overall TCO [in comparison to so-called Network Computers].”

Now, Dilger claims, Microsoft’s support for Windows Mobile is running dry and Gartner is looking for a new customer with equally deep pockets. Someone like Google.

The best quote in the piece, taken from Microsoft’s manuals on evangelism (and not necessarily directed at Gartner in particular):

“Analysts sell out – that’s their business model. But they are very concerned that they never look like they are selling out, so that makes them very prickly to work with.”

You can read the Roughly Drafted piece in its entirety here.

Gartner has not yet returned a request for comment.

[Follow Philip Elmer-DeWitt on Twitter @ philiped]