You can set the resolution to do either. My laptop (which is basically my DAW nowadays as it's sooo much better than my desktop) is a 17" widescreen, and I have the resolution set so it displays a true 16:9 widescreen image (not a regular 4:3 stretched). I use Nuendo, and it's super handy to have access to more faders on screen when the mixer section is on screen. It also allows for more of the audio to be displayed (the waveforms) even when zoomed in, which cuts down on scrolling.
I find it very handy to have a widescreen.