Windows Phone 7/7.5 is the mobile OS from Microsoft. It is a most promising OS in the Smart Phone space. It is new compared to IOS and Android but is steadily gaining the market. It’s Metro UI and touch interface have received applaud from all over the world and also won many design awards.
Microsoft has announced the release of windows 8 which will be the first OS which will run on Desktop and Tablet alike and along with that Windows Phone 8 is also announced.
What Microsoft has done with windows 8 will be revolutionary. All the applications that will be able to run on tablet and with few modifications it can be tailored to fit mobile. This will speed up application generation process enormously.
So, if your site does not have a mobile interface, be prepared to lose a lot of customers or be wise and choose mobile web design like millions of business already.