I'd go with hyphens for two main reasons. I am sure there are more.
-
It's a common best practice. Hyphens are used to to separate words in a keyword phrase (new-content).
-
It's a small win for usability because it is easier on the eye. http://www.yourbrand.com/somecontentaboutaproduct is harder to read http://www.yourbrand.com/than some-content-about-a-product. Think about it through the eyes of an interested party who finds the link from a social share. Getting design right isn't just about color, white space and layout, but how the overall brand appears.