Silverlight 5 will be available in second half of 2011

Here is a list of some of new features being introduced in SL5 from ScotGu's blog.

• Hardware video decode
• Trickplay
• Remote control support
  
• Better Databinding and MVVM
• WCF and RIA Services: Silverlight 5 now includes WS-Trust support.
• Improved text clarity
• Better printing support
• Out of browser support
• Better and faster drawing
  
• Automated testing tools
• Smaller download
• Faster performance

Watch ScotGu's keynote here