The future of Sony in the smartphone market has two major considerations for Windows Phone:
1) Will Sony make a Windows Phone 7 device?
2) Will Sony push their PlayStation platform on other mobile OSs?
The answer to the first is maybe. More specifically, Sony is keeping the door open to make a Windows Phone in the future, but as far as anyone knows, there's nothing immediately on the horizon. One reason for that is that some speculate Sony would not embrace a phone that makes the Xbox 360 its centerpiece. After all, this may seem to downplay Sony's own efforts in mobile gaming.
Sony though seems to be taking a mild mannered approach to the issue, suggesting that they are in fact, hardware/software neutral when it comes to their mobile PlayStation suite (prominently launching on Android). In a press event, SCE CEO Kaz Hirari stated:
We're focusing first on Android... There's also Windows [Phone], iOS and so forth, but we don't have the resources to make it compatible with everything from the start.
The statement is an echo of a recent meeting where Sony previously described the PlayStation suite as "hardware neutral". This seems to take out the argument that Sony won't ever do a Windows Phone either due to fears of competition in mobile gaming. In fact, we could imagine Sony doing a Windows Phone featuring Sony mobile gaming on it. But now the ball is in Microsoft's court: would they allow such a deal and partnership to go forward? This could be an interesting next few months and we'll try to grill Sony on this issue at Mobile World Congress in a few weeks.