That's not what's being patented. The gui menu to select placement of windows is what's being patented.
Did that exist before 2008?
I know I used window managers with almost the same grid square select in the 1990's. Not able to conjure up a screenshot yet. I did find one that's very close, here: http://www.badros.com/greg/papers/scwm-extensible-wm.pdf
That is clearly a UI for dynamic window placement and sizing, just not with the exact grid dynamic, though you can define new constraints, so it's possible it can do it as well. It's not the one I remember, but it's hard to Google up old UI's in HN time.
Given some time, I'm sure I could find something exactly like it.