jQuery Roundup: Isotope, Query, 1.5 Changes, File Upload
Isotope

Isotope (GitHub: desandro / isotope) by David DeSandro and Metafizzy is a layout plugin with lots of options and elegant animations. The basic Isotope demo repositions elements (literally) when the browser is resized. Elements can also be filtered, and it can cope with resized elements using the reLayout method.
Query
Query by TJ Holowaychuk is jQuery for the command-line. It uses Node and jsdom to provide nifty shell access to jQuery selectors and DOM traversal features:
curl http://twitter.com | query 'a#logo' | query img attr alt
# Returns 'Twitter'
Node is required, and Query can be installed using npm with npm install query.
jQuery 1.5 Changes
jQuery 1.5 Changes Part I by Garrett from Red Ventures discusses the new Ajax module in jQuery 1.5 with some details on $.Deferred(), which while incredibly useful, may seem confusing at first.
jQuery File Upload
jQuery File Upload (GitHub: blueimp / jQuery-File-Upload) by Sebastian Tschan is a jQuery file upload plugin that handles multiple files, drag and drop, progress bars, cancelled uploads, and a lot more features.
This plugin also optionally uses jQuery UI for additional interface features.