To me, it seems more helpful to think of all of these media sea changes as something the tablet could do, not something it will do. I read Mark Potts’ medium-by-medium list of the effects of iSlate as a sort of call to action for people in those media to do some serious thinking, planning and developing to be on the front end of that revolution if it comes. This could be traditional media’s second chance to be more proactive in finding ways to (gasp!) use technology to its advantage, after its first chance with the Internet was largely squandered.
The best way to keep crappy content from choking out good content? Keep creating and linking to good content. Google’s search dominance depends (at least in part) on its ability to lead users to the good stuff; makes sense to just produce quality stuff, link to it and pass it around, and let Google’s engineers do their jobs.