BigScreen is a partial realization of ideas I've been batting around for years, along with some significant previous work in window management.
A quick hack in '04 with firefox created a linked dualpane view where scrolling moves both panes.
Elastic Windows from HCIL @ UMD provides optimization for viewpane management. See context at citeseer.
The window stacking gesture from '01 does much the function of widescreen.