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." While the pinstripe-and-wingtip crowd is entitled to its opinions, we've got some pretty sharp stock pickers down here on Main Street, too. (And we're not always impressed with how Wall Street does its job.)

Given this, perhaps we shouldn't be giving virtual ink to "news" of analyst upgrades and downgrades. And we wouldn't -- if that were all we were doing. Fortunately, in "This Just In," we don't simply tell you what the analysts said. We also show you whether they know what they're talking about.

Today, we're going to take a look at three high-profile ratings moves on Wall Street: A downgrade for MCG Capital (Nasdaq: MCGC), but an upgrade for Corning (NYSE: GLW), and a new (and improved) price target for Manitowoc (NYSE: MTW). Let's dive right in.

Stifel sacks MCG Capital
A couple of weeks back, I caught flak from fans of American Capital (Nasdaq: ACAS) for suggesting the company's repurchase of 8.4 million shares might have been a "bad buyback." So far, it's looking like I was wrong, and the bulls were right, as AmCap shares march strongly onward -- and not just AmCap. Rising even faster have been shares of fellow business development company MCG Capital, which gained 8% over the past two weeks. But can the companies hold on to those gains?

Already, MCG is showing some slack, hurt by a downgrade to "hold" from ace stockpicker Stifel Nicolaus. So far, we don't know quite what it was that turned Stifel against the stock. Mainstream media outlets confirm that the downgrade took place, but that's about it.

Here's what we do know: First, that MCG sells for a cheaper forward P/E ratio than does American Capital -- 7.9 versus 9.8. Second, that MCG is buying back stock, just like AmCap. But third, that MCG pays its shareholders a dividend (13.6%!), which AmCap no longer does. It gets a Fool to wondering: If despite its superior stats, MCG is getting downgraded this week, can American Capital be far behind?

Piper sees promise in Corning
Turning now to happier subjects, a lot of investors have been looking at Corning lately, and liking what they see... Me, for one, as I've publicly endorsed the stock on Motley Fool CAPS. My Foolish colleagues Tamara Rutter and Dan Newman, to name a couple more. And this morning, Wall Street investment house Piper Jaffray made it four.

Corning, you see, held a meeting with some of its favorite analysts last week, and Piper came away impressed. While we're all on notice now that 2012 will be a year of "transition" for Corning, Piper thinks the company can get back on track by as early as 2013 and resume growing earnings again. Granted, consensus estimates have Corning pegged for only 4.6% average growth over the next five years -- but its industry is expected to grow closer to 16%. Unless you believe that Corning is a significantly lower-quality operation than the average "diversified electronics" company, it seems to me there's a whole lot of room for upward revisions of earnings estimates in this one.

In short, Piper thinks you should buy the stock, and I'm inclined to agree.

Manitowoc? Really?
"Psst! Buddy! Want to buy some shares in an unprofitable, cash-burning, heavily indebted industrialist? One that pays a negligible dividend yield of just 0.5%?" If so, then chances are your name is Longbow Research.

This morning, the upstart Ohioan analyst added 27% to its price target on cranes 'n' kitchen equipment manufacturer Manitowoc. Already bullish on the shares, Longbow now thinks Manitowoc could be worth as much as $21 per stub by the end of the year.

What's behind the optimism? Well, for one thing, Manitowoc just got done reporting earnings that showed crane sales up 40% year over year, and operating cash flow reaching levels not seen since September of 2009. Analyst guidance is positively exultant, with predictions calling for average earnings growth of -- better sit down for this -- 133% per year for the next five years (according to Yahoo! Finance).

Wow. Is that even possible? I admit I'm skeptical, in part because I'm not quite sure how you go about predicting profits "growth" in a company that's currently reporting negative profits... The fact that Manitowoc is still reporting negative free cash flow, and rising capex, on a trailing-12-month basis also gives me pause. Personally, I think a safer place to look for profits might be at Manitowoc's competitor-in-the-kitchen Middleby (Nasdaq: MIDD), which continues to generate strong free cash flow and more down-to-earth, but still robust, profits growth expectations of 17.5% annualized.

Foolish takeaway
Still, there's no denying that Longbow Research has a long record of success in making the most outlandish of picks. With a record of 59% accuracy on its picks, and a history of outperforming the market by about 13.5 percentage points per pick, Longbow ranks among "Wall Street's Best" stockpickers on CAPS. I might not follow their advice on Manitowoc -- but I wouldn't bet against 'em, either.

Looking for a safer, more dependable path to profit? Consider the Fool's all-star list of 11 Rock-Solid Dividend Stocks. You can read about them all in this free report.