Two notable features are interoperable with Windows Live Messenger, which was already present in the full version of Yahoo Messenger and message history, which saves chat logs on Yahoo’s server. Message history was also present in the full version of Yahoo Messenger, but it worked by saving messages locally.
Yahoo Web Messenger’s flash based interface is completely lovable. Once you load the page, you’ll never have to reload the page again (even to check your message history). Unlike Meebo, Yahoo Web Messenger has a tabbed chat interface. Whenever you initiate a chat or someone sends you a message, it’ll neatly open up as a new tab. It has advertisements as well, but it shouldn’t really be an issue as they are giving you all the above goodies.
Yahoo Web Messenger was announced on May 2nd, but I was not able to try as it was not available for my country at that time. If you look into the past, Yahoo had announced that they’ll integrate Yahoo Messenger within Yahoo Mail; so far the feature hasn’t been enabled for my account. It’s surprising to see a company like Yahoo do injustice to its users.
Just as a reference, Yahoo Web Messenger was built on Flex 2. You can try it by typing http://webmessenger.yahoo.com/ or simply http://web.im/
