Yahoo Messenger added to Mail Beta
For example, when you start to write an email, the "To:" box will tell you if the contact you're writing to is online and available for chat. And if you've already started writing an email but have changed your mind and decided to initiate a chat, Yahoo! will automatically copy the text you've written into the chat window.
If you receive an instant message while you're working on an email or participating in a chat with someone else, a tab will pop up in the background, alerting you to an incoming message while letting you work in the current window. Ryan Kennedy of the Yahoo! Mail team has a screencast up demonstrating some of the new features.
Overall it looks pretty nifty. In general I've been pleased with Yahoo! Mail Beta. The interface feels much more like an application than a web page. But there's a price to pay. While the interface is definitely zippier now than when it first rolled out, it's still not as responsive as Gmail. Yahoo!'s in the process of rolling out the Messenger update and my account doesn't have the feature enabled yet, so I can't say whether it's as responsive in real life as it looks in Kennedy's screencast. If you've received the update let us know, and tell us about your experience with it.