Keiji has just posted on the Messenger Developer blog that the Windows Live Messenger Library has been updated to version 2.5. Highlights of this release are:

• Easier access to most common contact properties

  • Contact status, display name, personal message, and display picture are now all accessible directly in the Contact object.  Applications no longer need to understand the concept of the current IM address for a contact.
• New Contact display name
  • The library provides a new property for a contact’s display name.  The library dynamically computes an appropriate value based on availability of nickname, IM display name, and IM address.
• Nickname support
  • Windows Live Messenger enables users to provide nicknames for their contacts.  Applications can now read and write nicknames from the Messenger Library.
• Methods to show and hide Sign-In Control
  • We have improved the reliability of the Sign-In Control.  We have also made it easy for applications to dynamically show and hide the Sign-In Control with show/hide methods.
• Item accessors for all collections
  • Applications can now directly access items in collections instead of iterating through the collections using enumerators
• Operator overloads
  • We have defined overloads for methods where applications often use the default settings
• Firefox 3.0 support
  • The library now works with Firefox 3.0.

To access these new features, your project needs to reference the new js file http://www.wlmessenger.net/api/2.5/messenger.js.