Very easy - the strategy is to take a huge ignored segment and hijack them with an offering to knock them off their feet.
One of the interesting news released today is Nokia prepping an App Store with almost 20K apps. The problem with this story is that it is going to be restricted to the newer Series 60, v3 phones.
However, there exists one platform in this world, that is largely ignored - even by its original creators. This is the Nokia Series 40 platform - designed for midrange phones and is the world’s most widely used mobile platform.
If I may say so, the most important aspect of such a move would involve typography - nothing jazzes up people more (though they do not realize it), as much as nice antialiased fonts. Which is why Google, got someone to create the Droid fonts for their Android framework.
There is a huge, untapped, largely-ignored customer base waiting to be taken over - the key is a sufficiently lightweight and jazzy looking mobile stack. If Carol Bartz wants to transform Yahoo - this is definitely one way to go about it.