Vertical Fisheye @ wonderland labs

I prefer a vertical scrolling list with a fishey view of the pages. (the mouse at the bottom emphasizes the last page in the series.)

Keep in mind that tabbing is much more frequent and reflexive than, say, pulling out a bookmarked page. And quite frequently the choices will be only between three or four open pages.

Most of the good ideas on this site seem to emphasize the tile approach which while visually impressive is not as reflexive as a click-drag across a vertical list of choices. 

The vertical list could be knocked back to an iconic display with a click of the page corner icon.