I probably should just shut up about them publishing the release saying it weights 24k, and I've seen people today screaming "oh, it like the good old times!", and then they realize that it says in breakers "(gzipped)" and find out that the actual script weight is 70k. For a comparison, minified the same way Prototype weights 72k.
But why I will never get tired of mocking jQuery users is that performance optimization graph John posted over there http://jquery14.com/day-01/jquery-14. In case they will fix it, I've saved a copy over here.
Basically what it says is that jQuery 1.4 makes 30'000 (oh yeah baby, thirty thousands) times less calls than 1.3.2. Well to be honest in just a few operations. Seeing people making things like that I couldn't resist it and fired up my trusty Shakker, which bluntly compares frameworks performance feature by feature.
So what do we see? They did optimized it awright. Certainly not 30'000 times, more like 30% in average. At least it looks okay in FF
But when you run the test in Safari and Opera, you can see that it actually getting slower in some operations
This is about it. You can find all my tests code over here Shakker
But good luck with the 2 weeks orgy though 8)