In which world do you live?
In the world I live, GIMP does not support CMYK, so I find it hard to belive that anyone serious would create a DTP workflow using it, unless they handled only black-and-white-photos. Moreover, in the world I live and work, PageMaker was more or less decommissioned a few years ago (and now lives on as a plug-in to InDesign), which makes the comparison between PageMaker and Scribe quite pointless. InDesign is mentioned perhaps twice, which also does not reflect the world that I live in, where people started abandoning the sinking ship named Quark somewhere around InDesign 2.0.
So, to be able to take this article seriously I would have liked to see comparisons to Quark XPress 6 and InDesign CS, not PageMaker. But I guess this article was written by a tech-journalist for programmers, and not DTP-people.
Face it, Scribe is not going to dent the sales of InDesign or Quark one bit. GIMP is a laugh in the DTP-world. It's not that I'm happy with this. Oh no, it's nice to see that OSS applications like Scribe are being made, but they can't compete on this market, not just yet, perhaps never.