Many Popular Windows Apps Ignore Security Options
Also, the DEP setting is opt-in on workstation SKUs (your app has to say that it wants it) -- for compatibility, and opt-out for server SKUs (your app has to say that it doesn't want it) -- for security.
The End of Non-Widescreen Laptops?
Depends on your IDE. If you're using a bunch of terminal windows running vi, then I might agree with you, although I prefer to have a couple of windows side-by-side.
If, on the other hand, you're using Eclipse or Visual Studio, which have a bunch of toolboxes and other panels docked to the left- and right-side of the IDE, widescreen starts to look attractive.