Some of the discussion here (and even more so in the media) seems to me like a tremendous dramatization of an incident that harmed no one and simply required an emergency landing. Something made a hole in the aircraft, pressurization was lost, the crew did exactly what it was trained to do, the aircraft behaved exactly as it should, landing was uneventful and nobody was hurt at all. It's almost a non-event. But I guess the hole looks good on TV.
People should be reassured by this, in a way, because even though a hole blew open in the aircraft, it still flew just fine, and everyone got down safely with nothing more than an exciting story to tell the grandkids. All the procedures worked. Nobody was ever in any real danger. That's quite unlike what the fictional Hollywood or mass-media verisons of the story might be. Everything worked by the book and everything went fine. Charleton Heston didn't have to be resurrected to fly the plane, and Joe Patroni could still sleep late.
Some media love having a nice big hole to photograph, although it's difficult to sensationalize it very much without any bodies. Fill the screen with the picture, talk about the "dangerous plunge" as if it were an accident rather than a deliberate and controlled descent, try to find a few passengers emotional enough to put on camera, and lower your voice when you mention that nobody was actually hurt (but be sure to mention the ones who vomit).
The only real concerns here are technical and cannot really be adequately addressed until an investigation is completed. Was this incident linked to the age of the airframe? Was it improper maintenance or operation? Was it simply a freak accident? Ultimately what the industry needs to know is the likelihood that it will happen again: if that likelihood is low, no problem, if it is significant, something will have to be done to reduce it to insignificance. Either way, I don't see anything to worry much about.
Personally I rather like the 747-400, so I hope that it turns out to be something Qantas messed up rather than an issue linked to the age or design of the airframe. Sometimes I get the (highly subjective?) impression that people are trying to find excuses to retire 747s just because they've been on the top of the heap for a couple of decades.