Sony Ericsson phones running on Android have been doing pretty well in the market. And as per Steven Walker, head of global marketing at Sony Ericsson, they will stick to the Android platform for some time. Even then, it doesn't mean that they have ruled out Microsoft's Windows Phone 7 competely.
In an interview with Pocket-lint, Steven said, “We've done a lot of work with Microsoft over the years. We’ve launched a number of 6.xx products, but we made a decision not to bring a product to market in the first wave. We absolutely maintain to keep an open mind towards Windows Phone 7. We continue to engage in a relationship with Microsoft, but we haven’t made any concrete announcement about when and how we would introduce Windows phone 7 into the portfolio.”
He’s clearly said that although Sony Ericsson is still concentrating on Google’s operating system, doors for Microsoft’s Windows Phone 7 will be open. They don’t intend to be “Android Forever” like Motorola and will make changes as and when needed.