It took some time to initialize, first time I launched, but since then it's been working blazingly fast, just a Desktop Application. Includes a Left Pane, where you got all the links to the Mail Folders, Calendar and Notepad. RSS feeds can also be added within in the mailbox only.
You click on a Mail folder and it is loaded in the right-pane of the Window, and that's where it is fast at. You can right-click on Mail Folders as well as on the messages to perform most of the tasks.
Double-click on a message in the list and it is loaded with full height, without a preview window. With Keyboard shortcuts similar to Gmail, the experience is much better and simpler.
Sign up for Yahoo Mail Beta here.
Those who've already joined Yahoo Mail Beta, can join this Yahoo Group
