Just out of interest I thought I’d take a look at the Olympic website and compare the size of the Olympic Stadium to Brisbane Road, the home of Leyton Orient. Using their maps (www.london2012.com/map.php), I zoomed in at the same level and took screenshots. I’ve photoshoped Brisbane Road ontop of the most recent aerial photo of the stadium (click image for bigger view):
From this it looks like the closest seats to the pitch at the olympic stadium will be about the same distance as the furthest seats at Brisbane Road.
I’m glad I won’t be watching football there.