I'm not a fan of drawers myself - not for contexts like Omniwebs tab drawer anyway. Drawers have always represented temporary stuff to me - you change something in it and then hide it again. For Tabs I would prefer a split view, as I have them open all the time and dislike the odd ungainly outline that a window and drawer makes.
A while ago I did a mockup of how I'd personally like the tabs to be:
http://www.hicksdesign.co.uk/images/omniweb/mockup.png