There are some really great things in here, it feels like the creators have grown this out of a lot of experience using jQuery, gathering up all the pain points and omissions over time. Even the little things like $.formParams, I always wondered why that wasn't in jQuery, whilst $.serialize is, the former seeming much more jQuery (or perhaps more JavaScript, maybe that's the difference).

Very impressed. I started listing a few I especially liked but then ended up listing the whole lot.