This is what I found on the official blog of the Yahoo! Mail Beta. It looks like Yahoo! has started integrating the Yahoo! Mail and Messenger into its new Yahoo! Mail Beta. If you are not using the all new Yahoo! yet, you should read my earlier post about how to get invited to the beta Yahoo! Mail.
The new integration looks awesome and definitely got me hooked since I now use the Trillian Messenger for my chat. This new combination of Mail and Messenger of Yahoo! is already implemented by Google for its GMail and GTalk applications. But the Yahoo! has done things sleek and sexy if I may say so! It is a very much blended look and it now has the feel and look of a desktop on a browser.
I heard people saying that the new Yahoo! Mail Beta is slow for access, but one has to agree that once the initial logging in process is over, it works as fast as any desktop based mail client.
Here is the official video of the new Yahoo! Mail and Messenger integration.