Instead of fairly robust 3.4% annualized growth, the government's next estimate will probably be closer to 2.2%, according to median forecast of economists surveyed by MarketWatch. Instead of bouncing back, the economy would have turned in its third quarter in a row of below-trend growth.

The first quarter also looks fairly tepid, with weak retail sales, falling homebuilding and growing signs that business investment isn't picking up the slack.

Revisions to the data are common. On the first pass, the government must simply guess at some of the numbers in the report, such as trade, construction spending and inventory building for the final month of the quarter. The average revision is 0.5 percentage points. But this time, the revision will be at least twice the average. And it would be the largest downward revision in 15 years.

Some economists say the downward revision isn't such horrible news. The main source of the revision was in inventories, which declined much more than initially thought.

Wednesday, the Commerce Department reported U.S. businesses worked down their inventories in December after a shard buildup in previous months. It was the slowest growth in inventories since July 2005. See full story.

The faster inventories contract so they are in line with demand, the faster production will resume in the nation's factories, the theory goes. That means growth should be stronger in coming quarters.

The other source of the downward revision comes from the trade gap. And although the trade gap is larger than suspected, it's up largely because U.S. consumers demanded more imports. That signals that the economy is fundamentally sound, the argument goes.

Still, one can't help but think that the economy has really and truly slowed, just as the Federal Reserve intended.

Maybe it's a Goldilocks economy, neither too hot nor too cold. Or maybe it's the fabled soft landing, with growth slowing just enough to ease the inflationary pressures without leading to a hard landing, otherwise known as a recession.

Or maybe the economy is at its stall speed, just one shock away from a bumpy landing. The bulls scoff at the dire predictions: Even a stopped clock is right twice a day, but these guys haven't been right in four years.

The bears counter that the Fed rarely achieves a soft landing; it almost always goes too far and pushes the economy over the cliff.

On the plus side: Employment continues to grow and real wages are actually rising. Profits are also up and corporate balance sheets are in excellent shape.

On the minus side: Consumers are strapped. They're in debt to their eyeballs and their homes are losing value every month. The refinance ATM has closed. The factory sector is weakening.