> Wrong and poor advice to subvert browser functionality. Alert the user to which input they are currently working with. Eliminates [tiresome] user guesswork and is conventional. Also helps the visually challenged.
If look at Google.com, the outline is a single pixel color stroke that replaces the gray stroke that currently exists when it's not in use.
When you look at Facebook.com, they don't have a highlight either.
On Facebook (not exactly a paragon of usability) it's there. Also tab around the page. Links are also highlighted in light blue.
Maybe it's my own view, but when a designer circumvents or subverts basic, conventional browser functionality it signals they don't know how to design for the web or they care more for their particular design than they do for the user's ability to process and react to the intended functionality.