Work under way to add sidebars to Google Chrome
Not yet at least. Work is underway, however, on building sidebars into Chrome's extension API. The awesome ASCII mock up was created by Chrome developer Aaron Boodman, who also references Aza Raskin's Viemo clip of the Mozilla Jetpack sidebar setup.
Persistent sidebars would be a welcome addition for any number of existing Chrome extensions -- like the many social networking, content clipping, and discovery extensions.
Curious what else is being considered for addition? Have a look at the Chromium Extension API Wish List. And before you ask, yes, "downloads" is listed and DownThemAll is given as the use case. I sincerely hope this is next on the list -- Chrome's download
The full sidebar API proposal doc is available after the break -- check it out!