Putting a bit of a downer on things - but you do know your browser is basically just IE7 with a different interface on top?
If you want to know what features to include, just look at other browsers out there - bookmarks, history, options and that sort of thing. The sky is really your limit here, you're never feasibly going to run out of things to include (though I personally think you should sort out what you've got before you put a load of new stuff in.)
Oh and you also need to seriously sort your window resizing out - you don't get any scrollbars when you reduce the size of the window and the elements don't expand to fit when you maximize it. That's a complete no-no!