Yahoo Inc. (NASDAQ: YHOO) Chief Executive Jerry Yang today promised good things to patient investors. Wall Street, though, wanted more immediate gratification from the fourth-quarter results and sent shares slumping in after-hours trading.

"While we will continue to face headwinds this year, we believe that the moves we are making will help us exit 2008 stronger and more competitive and return to higher levels of operating cash flow growth in 2009," said Yang, who replaced Terry Semel last year, in the earnings release.

Results in the latest quarter were, as expected, pretty bad. Net income was $206 million, or 15 cents per share, compared with $269 million, or 19 cents, a year earlier. The results beat the 11-cent average estimate of analysts surveyed by Thomson Financial. Revenue excluding so-called traffic acquisition costs rose 14% to $1.4 billion, a tad below analysts' estimates of $1.41 billion.

Once again, Yahoo is promising that things will get better. "We still have a tremendous amount of work to do, but we're confident we can substantially improve our users' experiences and achieve meaningful incremental monetization opportunities for Yahoo!'s own ad inventory and that of our partners," said the company's well-regarded President Sue Decker.

Wall Street has heard this story before.

Yahoo now must walk the walk as well as it talks the talk.

See the full transcript of the conference call.