I use Yahoo Mail for one thing: mail. I don't use the calendar, or the notebook, or the eleventy hundred facebook and other flavor-of-the-week apps. I don't want to run a Yahoo search or update my im status or look at obnoxious branding images. I just want to see my inbox, the emails I'm composing, and that's it.

This style strips out everything except for your actual mail, so you can focus on your messages instead of the distracting bits and bobs of the new interface. You'll save quite a bit of vertical space as well.