"Churnalism"
Nostrich says:
“Churnalism” was coined by a member of the National Union of Journalists,
[I]t signifies ‘the practice of regurgitating material, rapidly and under pressure, from outside sources without checking’.
By that logic, given the very definition of a tumblelog, would it be safe to call tumbleloggers “churnalists”?
Logically, yeah, tumbleloggers are “churnalists”. But even without the definition above, the term does sound fairly pejorative, which surely we don’t want?
Tumbleloggers don’t simply regurgitate like a lazy tabloid hack hastily copying facts from Wikipedia to meet a deadline. Many (but of course, not all) don’t even really tend to write that much, so perhaps comparisons to journalism are slightly unwarranted.
Some tumbleloggers carefully pick and choose their favourite things found on the web, more curating than churning. And some go for the “stream of consciousness”-style originally pointed out by Kottke, admittedly regurgitating, but filtering content and spreading it virally nonetheless. Even if this filtering is quite disparate (“I just post lolcats, XKCD comics and interesting bits from my botanical research paper”), it’ll be relevant to a certain group of the tumblelogger’s peers (or “followers”, to use the Tumblr terminology).
So perhaps “mavens” (as used in The Tipping Point) is a better term. Now just to coin a catchy phrase that expresses that idea…