New Yahoo Mail Beta - Quick Review
The New Yahoo Mail - Beta
The Approach
It looks like yahoo took a new approach, to present the online email experience in a traditional form. Yes, the new Yahoo Mail Beta does look like your conventional email clients like Thunderbird, Outlook, Eudora etc.
The User-Interface
The new User-Interface puts the folders to the left, message header list to the right and body of highlighted message below. At the first looks, it may not look different or one cannot understand “whats the big deal in this?”. For many users, who use a email client at work or home, it is difficult to use a conventional web email service. Because, everything takes time in the web. The usual problems like delays, white screens, slow server responses etc. Some of these issues were addressed by using frames/iframes etc. But there were no proven remedy.
It was until, the AJAX arrived. AJAX was widely accepted and web developers started adopting it for web applications. Yahoo’s new email uses AJAX and it competes with Google’s GMAIL. No screen refreshes, no slow responses. Click the folder on the left, and instantly the list refreshes on the right. Absolutely cool and excellent work. All work seamlessly. The most i like is.. the UI is almost similar to the conventional email client. It spares me from learning another web application. Makes my life easy ! 
The new Yahoo Mail is still in its Beta. So unable to write a detailed review. Will post a compilation of my observations later.
Conclusion
The New Yahoo mail looks promising.. fast.. and breathes fresh ! Good work guys!