The good news: Apple has big plans to maintain its impressive growth. The bad news: Those plans are going to weigh on margins for at least a quarter.

Even worse news for investors is that Apple won't release any specifics about those plans, leaving investors with little but uncertainty at a time when that’s all they’ve been seeing in the market.

As a result, Apple's stock tumbled a few hours after it announced its earnings for the quarter ended June 30--even though the company handily beat its own and Wall Street's forecasts for revenue and profit.

Apple's earnings for the quarter came in at $1.19 a share, above the company's own guidance of $1 a share and the Wall Street consensus of $1.08 a share. Revenue came in at $7.46 billion, compared with the Street's number of $7.37 billion.

So much for the good news. Looking ahead, Apple gave guidance that was conservative by even its own standards: It's once again expecting $1.00 a share in profit. It sees revenue at $7.8 billion. Analysts were thinking more like $1.24 a share in profit and $8.3 billion in revenue.

Then there's the matter of falling margins. Gross profit this quarter was 34.8 percent of revenue—again,  higher than most expectations but much lower than the 36.9 percent a year earlier. Apple C.F.O. Peter Oppenheimer said they would fall to 31.5 percent in the current quarter and hold around the 30 percent level for next year.

Some of the pressure on margins, Apple executives told analysts, is a "future product transition" that Apple executives refused to give details on despite repeated attempts by analysts to pry loose a hint. This mysterious new initiative could cost Apple profit through increased spending to develop a new product or by offering a price that is competitive to rival products.
    
"One of the investments we make is in new products that initially cost more because they deliver an entirely new value to the customer," Oppenheimer said on a call discussing the earnings. "We have some types of investments like that in front of us that I can't discuss today."

Already, the mystery product is leading to online speculation of what it could be.

Oppenheimer also addressed another matter of speculation, that over the health of C.E.O. Steve Jobs, that was reignited by a story in the New York Post citing some investor concerns. One analyst broached the question, prefacing it with multiple apologies.

"Steve loves Apple. He serves as CEO at the pleasure of Apple's board and has no plans to leave," Oppenheimer said. "Steve's health is a private matter."

The cloudy outlook surrounding Apple may not only dent Apple's stock, but other tech shares, as earnings for tech companies so far have been mixed. IBM and Intel proved surprisingly strong, while Microsoft and Google underwhelmed with soft guidance. The market had been looking for Apple to set a more decisive direction.

Instead, Apple, as shy as ever about tipping its hand to competitors, is essentially asking investors to maintain faith in its ability to deliver blockbuster consumer devices. Apple hasn't done anything to make us doubt it. It's just that the stock market is running a little short on faith these days.