Well, lately it seems that cross training is getting very big at local gyms. The idea is to use a different sport or style of training, such as running or weights or boxing, to enhance your own playing of a sport or style of training. I think this works well in writing too.
Novelists can learn from plays how to make the unit of a scene (time and place with characters dealing with a conflict) in a tight way. Fiction writers can learn from screenwriting how to use natural, concise dialogue. Nonfiction writers can learn about description from fiction writers. And everybody can learn about precise and musical language from poetry.
And presumably what we learn from the blogosphere is how to be opinionated in 100 to 1000 words, preferably with amusing pictures of cats.