Yahoo! Mail Beta arrives, claims to be at least twice as fast, safer, easier to use
There's an accompanying Yahoo! Developer Network blog post if you want details of the technical changes behind the new Beta. Most notably, Yahoo deployed a bunch of efficient HTTP proxies around the world that significantly speed up connectivity if you're not based near Yahoo's mail servers in the U.S. They also overhauled the rendering of the website itself, utilizing YUI 3, CSS3, and anything else that could reduce the amount of clunky HTML required -- gone are <table> elements!
All in all, the changes make for a much smoother Yahoo Mail experience. A lot of the cruft has been removed -- so much so that it looks a bit like Gmail, but with a "social" landing page tacked on the front. Let's not forget that Yahoo Mail, at least as of last year, owns the U.S. email market -- it's twice the size of Windows Hotmail and almost three times the size of Gmail. This update will affect, in a good way, how the majority of U.S. Internet users send email!