Thanks for nothing, Boeing (NYSE: BA). No sooner do you give me an excuse to say something nice than ... it's back to the old tricks.

Earlier this week, I had a couple of kind words for Boeing, praising the company's successful 747-8 test flight, which was made toting a companywide record-breaking load, and brought relief to the beleaguered shareholders of 747-8 suppliers General Electric (NYSE: GE), Spirit AeroSystems (NYSE: SPR), and Honeywell (NYSE: HON). But a leopard doesn't change its stripes, and this morning Boeing returned to its old pattern of overpromising -- and underdelivering.

Confirming what it's hinted at for weeks (and what I've predicted for more than a year), Boeing announced today that not only will its already-long-overdue 787 "Dreamliner" miss the "end-of-2010" delivery date, but that, best case scenario, it will begin delivering 787s to long-suffering customers such as All-Nippon Airways sometime in the middle of Q1 2011.

It depends on what the meaning of "is" is...
That's not a slip, Fools. It's a bellyflop -- the final shreds of management's credibility blown away in another gust of hot air. But worst of all is the lack of grace Boeing showed in making its latest admission. For years, the delays in 787 production have been the suppliers' fault. Or the union's. (Pesky Proletariat. Always whining about their sick kids needing health care, and how they need job security to pay their mortgages.) Or the suppliers again. Anybody but management.

So it's no surprise that this week, rather than suck it up and admit it was overoptimistic about the 2010 deadline, what did Boeing do? It blamed a supplier -- Rolls-Royce -- for not having engines ready to install.

A SODDI excuse (Some Other Dude Did It)
All year long, Boeing assured investors that this defect or that production delay would have no effect on production; that with a full year to work with, it would certainly deliver the 787 by year-end. When even that argument fell apart last month, Boeing pooh-poohed the worrywarts, promising that with a few tweaks to "instrument configuration," the 787 would be ready to fly. Now, Boeing informs us it's astonished to discover that Rolls-Royce might not have engines ready on time, due to a factory mishap that occurred four weeks ago.

My reaction? Sure, Boeing. Whatever. 2010, 2011, 2012 -- you'll get it done eventually, I'm sure. But quit it with the press released-promises, OK? We're tired of being misled.

Spirit AeroSystems Holdings is a Motley Fool Hidden Gems pick, but Fool contributor Rich Smith does not own shares of any company named above. The Motley Fool has a disclosure policy.