Microsoft .NET Framework 4.0.3 Beta Runtime Update can now be obtained.
New features introduced in this update
- SustainedLowLatency added to GCLatencyMode
- Support running Workflows in partial trust
- Enable WF messaging activities across multiple hosts
- XLinq and DataAnnotations added to .NET Framework 4 Portable Class Libraries
You will also find multiple fixes introduced in this Beta Runtime Update, KB 2599651 lists the new features and fixes in more detail and also provides a download link for this new update.