This doesn't surprise me that much since it seems like a natural progression. For one, media companies, such as newspapers and magazine companies cannot just be publication or media companies to be anything on the web. They also need to be software companies. I can imagine media/publication companies skimping on software because they think it isn't their business. No, on the web, software is their business because publication on the web is intimately connected with software.
Open source is a very popular form of publication on the web. So doesn't it make sense if you are a publication/media company and you have good publishable content (your software) to publish it? I see other benefits in this as well, such as more communication and wider dissemination about features of your website, and the possible software improvement and feedback about your software/website.
A great example of software developed specifically for a Web media company and open sourced is memcached, which is a memory caching system that was developed for LiveJournal.com. It's now used by other big sites such as Flickr, Digg, Wikipedia and TypePad.
Update: I just actually fully read that Linux.com article. That's a *great* article.
Derek Gottfrid, New York Times senior software architect:
"We're no longer just a print company, we're a technology company. We need to express ourselves in technological terms. The best way to do that is to give the developers a voice."