If you know Qwark you should really start playing around with InDesign. The Qwark people got lazy, thinking they were the only game in town and they just aren't keeping up with Adobe now. I am talking out ---my bottom--- a bit, as I'm not a graphic designer. My wife is one, though, so I pick up bits of info here and there (and keep her in programs like CS, Qwark, ATM/Font Folio, etc. -- there are benefits to having a computer geek husband).
Quark is still standard issue for a lot of the smaller 4-color press print houses (and a lot of the larger shops), which is a primary reason to keep it around. They don't like to upgrade to bleeding edge software since it can introduce so many little headaches.
I say this as a graphic designer who has tried all the various suites. I always end up back with Quark for final comping and I can tell you from experience that the press guys love me for it.
mrC