"Do you really need jQuery?"
I actually read about that site before the blog post, and later that day also saw this: You will probably need jQuery
Assuming you're talking about my blog post from this morning?
@julian yep, talking about that one. I've actually done some testing with a web app I developed on the performance between jQuery and vanilla JS. It's only sometimes that vanilla is really faster. (I did manage to get one jQuery routine from about 300ms to ~14ms with vanilla JS though!)