Apple states that although the present invention is primarily described in the context of a browser-based word processing system, the present invention could in fact be more generally applied to any system that renders textual information in a platform-independent manner and is not meant to be limited to word-processing systems or browser-based systems.
Boldfaced emphasis added by me.
Looking at that patent, it’s all obvious.
The breakthrough is the platform-independent rendering, not word processing collaboration.
The Trojan Horse is the word processing app. The invader is the rendering engine.
I would expect to see some patents from Apple about platform-independent image rendering and platform-independent interactivity. Although for the former, SVG and current JPEG might do. And for the latter, what else is JavaScript for these days?
If there is any actual technology behind this — and not just a flowchart for an idea — then we don’t have to pay any attention to Kindle format or ePub format for eBooks.
Apple has just announced their upcoming deaths.
Mike Cane’s xBlog 
What’s the big deal? This idea is not new.
The patent is both obvious and overly broad. It would never stand up in court.
Unless there is technology Apple has developed behind it. But I’m beginning to wonder how many Apple patents are pre-emptive moves ala Paul Allen’s so-called Intellectual Ventures. Apple has to put up or shut up on this one.
There are too many suits affecting Apple and what better way to get ahead of the game than by patenting.
What your problemf with Apple, they can do what they like so can you, patent a few good ideas and sit on them and wait for the motherlode to come later.
You have the mentality of a gambler, not a productive person.
After reading the article on Patently Apple, from my experience with patents in a wide range of technologies, and my understanding of the current problems with rendering, I find this neither obvious (in the patent sense) nor overly broad. It does depend on the technical solution to the problem, and I’ll have a look at the original patent application when I have time, but based on this information, it looks to me like this patent is absolutely brilliant (for Apple) and could stand a good chance of being defensible. I would take this application very seriously.