Quark has (and always had) a good business model: get the big players in the graphics industry to use Quark and the rest have to come in line.
The industry is a slow-moving beast, and Quark is still very much in use, every day. A fancy new program isn't going to get a newspaper to change applications when it takes something like an earthquake to get them to replace a 5 year old computer. For many of Quark's corporate users, OSX support is only important come hardware upgrade time, and that's something many do reluctantly.
When the bean counters hear that the main application doesn't run on new hardware, their eyes mist over. "If only all buying decisions could be postponed so easily", they think to themselves.
Adobe InDesign may yet win the battle, but (lucky for Quark) it's not over yet. There are many examples of better products and/or customer support that don't translate to sucess in the computer industry (not to mention most other industries).
If you use Quark, keep using it. When time comes to shell out real cash, then make an informed decision.
The sad thing is, Quark KNOWS that all they need to do is carbonize the application with minimal new features in order to 'win over' the majority of the exisiting industrial QXP users.
Although, there really is nothing great and looming left to improve upon in regard to the application itself - a little more stability, perhaps fix the image preview issues a la InDesign, and coupled with Quark 5's contextual menus function they'll be rocking! I just hope that all of this waiting isn't to allow Quark to introduce some crazy ass feature that causes the print industry mondo headaches. I'd rather they implement additions via it's extensibility features.
Actually, they also really need to accommodate newspapers more - a lot of us use fairly proprietary xtensions and applications for ad tracking, billing, etc. and all I hear from our developers are complaints that Quark are always dropping the ball when it comes to coding support and program structure, etc.
I think Quark dropped the ball on OS X they knew way ahead of time that Apple was going to change the Mac OS. The only saving grace for Quark is there huge customer base and nothing else. I still think that it was a bad decision for Quark not to stop the development of 5 for the classic Mac OS and restart to build it for OS X in the end it would have been a better product than the crapfest that is Quark 5 now, Quark 4 still had legs underneath it to continue sure it doesn't have all the nifty frills that Indesign has but it's still Quark XPress.
And another thing: Adobe have to severely Quark-a-cize™ it's interface in order for most newspapers to accept it as a replacement. Can you IMAGINE the breadth of the re-training that would be involved to replace an application that almost all of your production and newsroom employees have been using since the mid-eighties????
I've done the math at our plant... InDesign is too scarey a transition to face realistically in a 'traditional' QXP newspaper production environment.
I don't have the expereience wit either to say definitively, but I found a very interesting article on the whole thing over at Daring Fireball called The Sticky Business of Page Layout. I find the more I read John Grubers stufff, the more respect I have for him.