If intense rivalry over handsets, operating systems and pricing plans was not enough for key players in the mobile world, add mobile applications as the new battleground for gaining customer mindshare and spend.

As this week's Mobile World Congress in Barcelona, Spain, will doubtless have proved, every major player in the mobile world will fall over itself to debut apps for mobile phones.

Brands such as Google's Android Market, Research In Motion's BlackBerry, Nokia, Microsoft and Amdocs as well as a host of wireless carriers and infrastructure providers are slated to open new app stores with free and priced downloads for mobile phones. It is obvious: all have Apple envy.

And who can blame them? Apple now has more than 20,000 apps for download from its app store. More than 500 million downloads have occurred since the last summer, proving that apps will perhaps play the same role on mobile that software does on the wired Internet.

But just because it's easy to set up an app store or create an app doesn't mean that brands have to enter that business. One of the biggest challenges in the mobile space is the utter lack of focus in the industry.

Put simply, mobile brands haven't learned that they can't be everything to everyone. A handset maker that also produces apps and content, places advertising and acts as a media buyer risks losing its brand essence. What does it stand for?

Apple byte
Few companies can pull off what Apple did: launch a mobile phone with a platform that's completely hospitable to in-house and third-party innovation.

For Apple, it is not the product but the customer experience that matters.

That is something few mobile phone manufacturers or wireless carriers understand. Their marketing or products rarely inspire desire. Consumer purchases of their products or services are made entirely on a rational basis -- phone features and pricing plans.

The Apple iPhone, on the other hand, is positioned as the center of a new ecosystem for other products and services to revolve around.

In a way, what Apple has done with the iPhone is what Google did to the Internet: become a gateway.

The more people create apps for the iPhone and iPod touch, the more they will generate downloads due to scale and the economies it offers. Apple is becoming the de facto standard for apps by sheer force of market timing and market demand.

For those charging for the apps, the Apple App Store is quickly turning into a revenue generator that is almost akin to what eBay did for small retailers and entrepreneurs in the late 1990s and early 2000s.

Who knows, Google's Android Market or Microsoft or Yahoo may dent Apple's dominance of mobile apps. But not if they dither or balk at risk. Apple may have paved the way for these players, but it's also way far down the road for its rivals to catch up.

Apps blossoming into mobile channel
In addition to carrier on-deck portals, SMS and the mobile Web, apps are on their way to becoming another means to access mobile content and commerce.

Apps offer tremendous branding value to its creator. A weather.com app on the iPhone, for example, is guaranteed to be used several times each week. So will a mainstream news publication's app for quick updates without having to visit the mobile Web.

From a retailer's perspective, that app sitting on the Apple iPhone home screen is valuable real estate. It is also a statement by the consumer to reflect his or her affinity with causes -- what do you think a Patagonia app icon on the iPhone home screen says about the person?

So marketers must greet this profusion of app stores with glee. But, given limited resources in this slow economy, they also must make calls for which platforms to develop apps.

Ideally, marketers should create apps for Apple's iPhone, Google Android Market, Research In Motion's BlackBerry, Nokia's Symbian, Microsoft's Windows Mobile and Yahoo Mobile. There may be another couple of platforms with international reach that also deserve apps.

Of course, not all marketers will be able to afford apps for multiple platforms.

But, sooner or later, technology will be deployed that formats apps for the appropriate handset and operating system. This is already common practice for mobile Web sites seen on 1,600 different handsets with varying Web browsers.

However, for that to happen, the app stores and the device manufacturers will have to collaborate on some degree of commonality. Indeed, the need of the hour in the mobile space is common standards.

From the way it's shaping up, this seems to be the year of mobile apps. Expect Apple to announce either late spring or early summer its billionth app download.