Better late than never: Research In Motion (Nasdaq: RIMM) has formally announced that its PlayBook tablet, which launches April 19, will support Android apps. It mustn't have been an easy decision, as management guided current-quarter earnings below expectations to increase spending on the PlayBook. Some of that increase is for marketing, but some is R&D to adapt the PlayBook to run Android.

RIM's BlackBerry platform is facing double threats from Apple's iPhone and iPad and from mobile devices that run Google's Android operating system, such as Motorola Mobility's (NYSE: MMI) Xoom tablet.

An inelegant solution
Applications are typically a critical factor for buyers. For app developers, the money is where the most popular operating systems are. For the operating systems, getting lots of good apps -- and getting them first -- is a winner-take-most game.

The bad news for BlackBerry fans is that the PlayBook will run app-player software that runs Android. This "non-native" approach typically creates a noticeable performance drag. What's more, Android apps for the PlayBook will be available only through RIM's BlackBerry App World, which is reputedly not user-friendly. RIM management probably understands the limited appeal of this approach, because it also announced tools to make it quick and inexpensive to adapt apps to run natively on the PlayBook.

Android vs. iOS
Research In Motion's decision to make its PlayBook tablet Android-capable is an endorsement of Android's growing importance in the tablet and smartphone wars. Furthermore, Android could well see gains from the introduction of the Honeycomb version of its OS designed specifically for tablets.

RIM's decision underscores the challenge that Hewlett-Packard's (NYSE: HPQ) and Microsoft's (Nasdaq: MSFT) mobile devices -- which also have differentiated operating systems -- face in competing with Android and Apple's iOS. To be sure, HP has also touted quick, easy porting of apps to its webOS. But that strategy is more likely to keep it in the running than to propel it to a leading position. 

Foolish takeaway
Research In Motion's decision to adapt its PlayBook to run Android apps, and to create tools to make it faster and easier to adapt Android apps to run on the PlayBook, underscores the market success of the Android operating system. It's likely to help sales of PlayBooks to BlackBerry loyalists. But it's also a defensive maneuver, and questions remain about RIM's ability to fight off Apple and Android products in a winner-take-most game.

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Fool contributor Cindy Johnson owns shares in Microsoft. Google and Microsoft are Motley Fool Inside Value recommendations. Google is a Motley Fool Rule Breakers choice. Apple is a Motley Fool Stock Advisor recommendation. The Fool has written puts on Apple. Motley Fool Options has recommended a bull call spread position on Apple and a diagonal call position on Microsoft. The Fool owns shares of Apple, Google, and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.