"Fool me once, shame on you. Fool me twice, shame on me ..." But once the game of tomfoolery gets close to double-digit rounds, Boeing (NYSE: BA) investors have to start wondering: Who's fooling whom? And it's a question that becomes all more realistic with today's seventh official announcement of a delay in delivery of its 787 aircraft. Three years overdue and counting, Boeing assured us this morning that it's got the problems under control at long last and will deliver its first 787 to All-Nippon Airways in July.

Clearly, many people have been fooled by Boeing's repeated promises to deliver the "Dreamliner" by such-and-such a date ("Honest, we really mean it this time.") Hopeful customer United Continental (NYSE: UAL) is still waiting patiently, but Delta (NYSE: DAL) has all but given up on ever getting its planes, pushing its order off until next decade. General Electric (NYSE: GE) is still playing nice, but fellow supplier Spirit AeroSystems (NYSE: SPR) recently decided enough was enough and demanded it be paid to wait.

But lately, folks have begun to wonder if even the alleged fool-er (Boeing) has more of a clue when its Dreamliner will be ready for prime time, than do we, the alleged fool-ees. A few months back, as you'll recall, when new problems flared up in the 787's electrical system, the airplane analysts at Morgan Stanley argued that Boeing was underestimating its difficulties, and the 787 program would be set back a full year by the disaster. The warning made itself felt on the stock price, which promptly plunged to the low $60s.

But perversely, that got me thinking that maybe, just maybe, the pessimism was getting overdone. Clambering way out on a limb last month, I laid out a list of several news items that could potentially revive Boeing's stock price; chief among them was Boeing confirming that it would deliver the 787 in less time than Morgan Stanley's predicted year. (Other potentialities, in case you're interested, might include the Pentagon choosing to replace some of its Lockheed Martin (NYSE: LMT) F-35 fighter jets with Boeing-built F-18s, or further successes in Boeing's other civilian airplane endeavors, such as expanded 737 orders at rising airline titan Southwest (NYSE: LUV).

One out of three ain't bad
So far, Boeing stock is reacting well to the first positive prediction I made. For the good news to continue, though, Boeing must actually deliver on the deadline it's set itself -- then move on to deliver on the rest. Here's hoping we don't get fooled again.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.