OK Rated 5 out of 5 stars
mmm, looks interesting. But i only use google. It could be more usefull (and productive) if it just list my own search engines (the search engines that i have installed in the search-bar), and not those what you think i could use. Also i think that you must put an option to let the user hide the bookmarks and/or change as they wish.
At this moment, it looks more a sugestive way to make the user go to the those bookmarked items than something realy productive.
I give you 5 stars for your motivation.