It's not mentioned anywhere on the site, but it does do that. Unfortunately, the browser history doesn't contain as much data as boomtango tracks (the full content of the page, any information we grab off the dom, thumbnail previews) etc. It's still handy, but not quite as full featured as the history you generate after it is installed.
Super idea, this has been a major annoyance to me in the recent past, the inability to find stuff that I know I've read for sure.
First comment, please make it so that it will import all the history from the browser that it is installed on (if someone should want that).
thanks !