Well, there's two parts to the business - the news gathering and distribution but also the printing business.
There's all the usual suspects - a content strategy, a future news publishing platform play, buying influence or a trophy. However there is also the simple issue that large scale printing facilities cost a fortune to set up. Washington Post's smaller printing facility (which apparently was sold in 2010) cost around $230 million to build. Its printing facility in Springfield is said to be a monster.
Is this their intention? No idea. It's pure speculation.
Still, there's money to be made in printing. How else do you think we're going to get ubiquitous computing without electronics flowing off the back of massive printers measured in many km per hour.
I've a really old and out of date report on this from 2006. It's fairly useless now (other than general interest) but if you want to know more on the subject then I'd look at the work that Kate Stone is doing or Bruce Kahn.
Anyway, my view is the news business is interesting and there is lots of overlap with Amazon's current properties. As for the printing business, well if the time, tech and capabilities are all right then this could be the bargain of the century. Why buy a newspaper to do this? Unless you wanted to clearly signal your intentions to competitors by buying up or building printing capabilities then it's the best way I know to silently slip into the field.
Of course, with Google's purchase of Motorola most people are talking about the patent portfolio and their latest range of smart phones with the customisations available in the Moto X. What people might not realise is that Motorola also has some serious history in printed electronics at large scale. We might actually be watching the carve up of the future of manufacturing by two tech giants.
For those who have never seen flexographic, offset or gravure printing of electronics then this video [removed link, now defunct 30/03/2015] might peak your interest or the following CNET article.
But then again, maybe the analysts are right and Bezos just bought a newspaper and it's all about the content, influence, a trophy, a news platform play or a bit of them all. I wouldn't however simply ignore the printing facility though.