Since I recently covered some of the stocks that I see making waves in 2008, I may as well dig into the companies that may tumble in the year ahead.

In the spirit of full disclosure, I'll concede that just one of the four potential turkeys that I singled out last year imploded.

Through

11/13/07

eBay

11%

XM Satellite Radio

4%

Adobe Systems

(1%)

WCI Communities

(76%)

To be fair, just one of the four stocks went on to beat the market. With the average pan off by nearly 16%, maybe I'll go ahead and pin that article up on the fridge. It certainly worked out better than my batch of buys from last year.

OK, let's move on with this year's list.

Research In Motion (NASDAQ:RIMM)
You've got to love the BlackBerry. That doesn't mean that you have to warm up to the BlackBerry maker. Research In Motion has a history of chewing up bears like me and spitting them out as converted bulls, but I'm not buying it.

At more than 50 times this year's projected earnings, Research In Motion isn't cheap. Things get a little prettier if you go by the forward earnings multiple of 36 come fiscal 2009 (which starts in a few months), but what happens if someone comes up with a better BlackBerry?

Between the iPhone and Google's (NASDAQ:GOOG) new open platform initiative that has landed dozens of willing partners, the mobile landscape will change in 2008. Cell-phone makers are tacking on smartphone features. Service will get cheaper. BlackBerry will still be around, of course, but the playing field will be more crowded. The shares? Cheaper.

Salesforce.com (NYSE:CRM)
It's hard to root against Salesforce. The company reinvented enterprise software by providing Web-stored applications to corporations at a fraction of self-stored solutions. It's the poster child for disruptive technology.

However, what happens when the disruptor gets disrupted? Software behemoths -- and even search engine rock stars -- have awakened to the promise of cloud computing. Despite its presence, Salesforce has only been able to put up meager profitability.

Unfortunately, Salesforce trades at too high a multiple (in the hundreds -- even on a forward basis) for a company that is swimming around in a pool that is about to get pretty crowded. You don't want to be around when cash-fat giants break into a belly flop competition.

Netflix (NASDAQ:NFLX)
Brand me a masochist, but I'm going to toss a stock I actually own into this bonfire. I've been a shareholder and subscriber of the service for five years now, but I'm still troubled after the DVD-rentals-by-mail industry suffered its first sequential dip in total subscribers this past quarter.

Since it was rival Blockbuster (NASDAQ:BBI) that took the subscriber hit, Netflix investors seem to believe that they are immune. If anything, they see Blockbuster's loss as their gain. Check that, though. Netflix couldn't even grow by the sum of Blockbuster's defections. The overall pool of subscribers contracted -- from 10.3 million in June to 10.1 million in September.

2008 will be important. Early on, we'll receive confirmation as to whether the market peaked back in June. Toward the tail end of 2008, digital delivery companies that have been off to sluggish starts will have the opportunity to grab larger market share chunks as more homes go Wi-Fi. Sure, Netflix has a slick digitally delivered rental service. The rub is that it will be tougher to stand out. Netflix and Blockbuster were the only two companies to build out the distribution center network necessary to get the mail-delivered model right. When it comes to broadband, countless providers and even the studios themselves will make this a cutthroat market.

Microsoft (NASDAQ:MSFT)
The world's leading software company hit a multiyear high after posting stellar fiscal first-quarter results last month. Why bet against the champ? Why challenge what sharper analytical minds than my own have deemed as worthy for Inside Value newsletter subscribers?

Where do I begin? For starters, it's hard to take a company seriously when it's losing money in the chunky-margined playground of online services. Microsoft is doing a lot better in its software stronghold, but the same cloud computing movement that put Salesforce.com on the map now finds companies like Google putting out Web-based productivity applications. Open source solutions continue to be pesky competitors for Microsoft on the operating system, mobile, and Web browser platforms that it dominates.

Sure, Microsoft got a boost this year from the Vista upgrades. What will it do for an encore? With the playing field getting flatter and flatter, it's going to be hard for Microsoft to continue to justify fresher highs in the near term.

Putting it all together
I didn't dig into the subprime lenders or homebuilders. That's yesterday's carnage. I went with four quality companies that are unlikely to implode in 2008, but I also see high hurdles for them to keep up with the rest of the market in the coming quarters.

Some of the stocks are priced too richly at the moment. They all face a more competitive landscape in 2008. It's a dangerous combination. Be careful out there, my friend.

If you like to look ahead when you invest, you may be just the kind of subscriber to get the most out of the Motley Fool Rule Breakers newsletter service. Rick is a part of the analyst team there. There's a free 30-day trial subscription offer waiting for you, if you want to check it out. Netflix and eBay are picks in the Motley Fool Stock Advisor newsletter service. Microsft is an Inside Value recommendation.

Longtime Fool contributor Rick Munarriz always believes in being fashionably early, and he does own shares in Netflix. He is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.