I don't know that other forms of media are changing to be more like Web writing as much as they are changing in order to keep the interest of a faster-paced society. I've noticed that newspaper articles inparticular remain the same length, including all of the important information, but they are sure to highlight the main points in the very first part of the article. It seems as though writers of these mediums are well aware that their readers' attention span is more likely than not short, and thus get all of the important facts out immediately. However, unlike Web writing, which would condense information and merely leave it at that, it seems as though news writers still go into detail later on in the article.
A key difference in the writing of magazine articles after the advent of the Web is the inclusion of Internet terminology without explaination. In magazines such as People, which average Americans read on a daily basis, there are multiple references to AIM, blogging, online polls, etc. These are things that, prior to the popularity of online writing, would have been explained in depth if used in an average writing medium. Likewise, magazines for teens (such as 17 and YM) use AIM abbreviations much more often without explanation. In many of the editorials, as well as even some of the less sophisticated articles, it isn't rare to see an "lol" or "j/k" written with the assumption that all readers understand what is inferred.
I feel that these things are the key changed in the writing of other mediums since the advent of the Web. I don't know that newspaper and magazine writing will ever change to be more like Web writing so long as they remain in print format, because as long as they do they remain a separate genre of writing. It's almost like different forms of music ... with the advent of rock and roll, jazz and country didn't die out or totally become rock, they just changed a little bit for a time. I think that any evolving media will have similar changes.
