Here's some useful information from the documentation team:

The recent release of the Windows Phone Developer Tools January 2011 Update includes bug fixes, a new emulator, and utilities. Alongside the release of the tools we have also published an update to MSDN that focuses on documenting key aspects of this release, known issues/limitations and additional content for developers. The highlights of this release are listed below and also available in the What’s New topic on MSDN.

 

RELEASE HIGHLIGHTS

§  NEW DOCUMENTATION

o    Release Notes for the January 2011 Update

o    How to: Test Copy and Paste in Windows Phone Emulator

o    Deploying and Testing on a Physical Windows Phone Device

o    Troubleshooting Windows Phone Developer Tools

o    Frame Rate Counters in Windows Phone Emulator

o    New VB code samples

§  Keyboard Input Scope Sample

§  Model-View-ViewModel Pattern Sample

§  Silverlight Sound Sample

o    Bing Maps Silverlight Control – Working with Pushpins in the Map Control

o    Bing Maps Silverlight Control – Setting the Map View

§  UPDATED DOCUMENTATION

o    Performance Considerations in Applications for Windows Phone

o    Bing Maps APIs are now included in the class library reference

§  Microsoft.Phone.Controls.Maps

§  Microsoft.Phone.Controls.Maps.AutomationPeers

§  Microsoft.Phone.Controls.Maps.Core

§  Microsoft.Phone.Controls.Maps.Design

§  Microsoft.Phone.Controls.Maps.Overlays

§  Microsoft.Phone.Controls.Maps.Platform