At The Motley Fool, we poke plenty of fun at Wall Street analysts and their endless cycle of upgrades, downgrades, and "initiating coverage at neutral." So you might think we'd be the last people to give virtual ink to such "news." And we would be -- if that were all we were doing.

But in "This Just In," we don't simply tell you what the analysts said. We'll also show you whether they know what they're talking about. To help, we've enlisted Motley Fool CAPS, our tool for rating stocks and analysts alike. With CAPS, we'll be tracking the long-term performance of Wall Street's best and brightest -- and its worst and sorriest, too.

And speaking of the best...
Shareholders in perpetually struggling PC maker Dell (NASDAQ:DELL) got a gift this morning, in the form of an upgrade to "outperform" from Cowen & Co.

Citing a string of layoffs at Dell -- 3,700 in the first quarter, another 1,900 likely to leave in the second, and perhaps 2,225 more by year-end -- Cowen believes Dell can slash well over $100 million from its quarterly operating costs going forward. This, combined with new PC and notebook offerings that should boost sales to both retail and corporate customers, has Cowen predicting a 25% rise in the stock price over the next 12 months.

So far, so good
With the stock already up 4% in response to the upgrade, Cowen's predictions are well on their way to becoming a self-fulfilling prophecy. But just how likely is it that the remaining 21% are on their way?

Let's go to the tape
For clues to Cowen's stock picking prowess, we turn once again to CAPS for a glance at the banker's record. What we find there, however, is a bit of a mixed message. On the plus side, Cowen's made some very nice picks among companies closely tied to the PC industry:

Company

Cowen Said:

CAPS Says

(5 max):

Cowen's Pick Beating S&P by:

SanDisk (NASDAQ:SNDK)

Underperform

***

29 points

Intel (NASDAQ:INTC)

Outperform

****

28 points

EMC (NYSE:EMC)

Outperform

*****

2 points

But on the flip side, it's made numerous gaffes among the semiconductor shops that build PC electronic innards:

Company

Cowen Said:

CAPS Says

(5 max):

Cowen's Pick Lagging S&P by:

NVIDIA (NASDAQ:NVDA)

Outperform

****

40 points

Texas Instruments 

(NYSE:TXN)

Outperform

****

20 points

Marvell Technology 

Outperform

****

13 points

Over all, Cowen continues to rank in the top 20% of investors. Unfortunately, it does so not because it is usually right, but rather in spite of usually being wrong. On average, fewer than 48% of Cowen's picks "work out" for the investors who follow its advice. How does Cowen manage to place so highly despite guessing wrong more often than right? Mainly because one pick in particular -- solar power play First Solar (NASDAQ:FSLR), has worked out brilliantly.

But what about Dell?
Dell, unfortunately, is not generally considered a force to be reckoned with in solar power -- PCs and notebooks, absolutely. The occasional flat panel TV or iPod knockoff? Sure. But home-PC don't play solar.

Nor do I believe you should play today's Dell upgrade. Selling for 18 times earnings, Dell doesn't looks like a bargain relative to the rate at which most analysts expect it to grow -- less than 13% per year. While the stock's a bit cheaper when valued on its free cash flow (the price-to-free cash flow ratio works out to a little under 15), that still tells me Dell is at best a "hold" at this valuation. It's not yet a buy.