Yeah, knit cap or stocking cap is what I've always known them as. I'm assuming the goofiness/silliness I personally attach to the word "beanie" has been excised. After all, you couldn't be much of a hipster if you were purposely doing something you knew was defined as goofy.
"Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly, and applying the wrong remedies." -- Groucho Marx