There already were guides for Android, help for iPhone developers (and Symbian QT) but now there is even more guidance based on migration samples and a SQLLite to SQL Server Compact database conversion tool.
There is a series of samples to help migrate iPhone and Android apps over to Windows Phone. The content is available here for Android, and here for iPhone. For each sample, you’ll find the source code on Android/iPhone, the Windows Phone ported version and the porting notes.
For Android developers, there is also a “10 simple tasks: tips & tricks” article, which explains how common simple tasks performed during Android development can be done when doing Windows Phone development.
Cool huh? And it doesn’t stop there, they’ve also included a sample “Notification Service”, which shows how to build a multiplatform push-notification services supporting the different providers used by Android, iPhone and Windows Phone. Documentation is available here and sample code is here.
And what about the tool? Windows Phone 7.5 “Mango” includes relational database support by way of Microsoft SQL Server Compact (SQLCE). SQLite2SQLCE is a tool developed to make the conversion process simple by converting a SQLite database into SQLCE while simultaneously creating the default classes needed to incorporate the new database into your Windows Phone application and more….
You can read the whole story over on The Windows Phone Developer Blog