At MWC 2011, Microsoft just announced a number of improvements for WP7 including the timeline for when its first update will be pushed to devices.
The update with app-loading performance improvements and copy paste support we demoed back at CES finally got a more specific release date - it's slated to launch in early March. A number of other updates are slated for 2011, though Microsoft wouldn't assign a specific date. Those updates include multitasking support for 3rd party applications, better cloud synchronization, more web-services built into hubs, and a completely new web browser. http://bit.ly/fxjbYg