On my last flight to Europe on a Wide-body jet I had the honor of sharing my share of an 8 seat wide row with a decidedly non-personal space minded big framed guy. No matter what I did all flight long, I could not keep the guy (awake or otherwise) out of my seat space. His elbows never entered his own space for the duration of the flight, and whenever we retrieved his phone/iPod from his breast pocket I had to "wax the car" to keep from getting my nose busted.
That flight was on-board an Airbus A330 class jet. The seating arrangement on these happens to be the old standard 2-4-2 arrangement.
But it would seem that despite our tendency as a species to be getting wider, the seats on the planes we ride are getting narrower.