There are lots of new features in this preview version but not all the old features are incorporated yet. For example, new email notification is still missing along with no webcam, no voice, plugins, photo sharing, IMvironments, audibles etc. But the new features make it a worth try as you can still login to Yahoo Messenger 8 or 9 if you want as this is installed separately.
Here are some of the best features
New interface and there are no more the drop down menu style for changing the settings. You click the Main Menu button at the top which opens a comprehensive settings page. It’s more like the ribbon in Microsoft Office which has all the features and settings listed down rather than in the form of drop down menu.
Also you can resize the size of the contacts and you can list them side by side or by the traditional list down method. The usage is more like changing the views in Vista Windows Explorer.
You can chat with different people in individual windows are put together in a single tabbed window. Drag and drop windows to merge and you can also drag out a tab to form a new window. You can also do that by clicking explode or implode conversation at the bottom of the window. Check here to how you can also use tabbed windows in Yahoo Messenger 8 or 9.
Choose different colors for different windows for easy identification.
The all new Yahoo Messenger Emoticons which are more live!
Send files as large as 2GB!
Keep your favorite contacts in the Vista Sidebar to keep in constant touch. Just click the sidebar to chat with them or send any files.