Well the performance improvements are of course something I appreciate, but I guess I can't say it's a "finally" since it's something that's subject to constant improvement :) The DOM-building (Quick Element Construction) syntax looks really convenient, and the detach
method also looks quite usable: it allows you to temporarily remove an object from the DOM, but keeps all the handlers assigned to it, so that it'll work just the same way, when reinserted.
I guess there's not so much a lot of things that I've been missing, but now that these new features are out there, there's a bunch that I'm anxious to start using :)