Arm your vuvuzelas: WordPress 3.0, the thirteenth major release of WordPress and the culmination of half a year of work by 218 contributors, is now available for download (or upgrade within your dashboard ). Major new features in this release include a sexy new default theme called Twenty Ten . Theme developers have new APIs that allow them to easily implement custom backgrounds, headers, shortlinks, menus (no more file editing), post types , and taxonomies . (Twenty Ten theme shows all of that off.) Developers and network admins will appreciate the long-awaited merge of MU and WordPress , creating the new multi-site functionality which makes it possible to run one blog or ten million from the same installation. As a user, you will love the new lighter interface , the contextual help on every screen, the 1,217 bug fixes and feature enhancements , bulk updates so you can upgrade 15 plugins at once with a single click, and blah blah blah just watch the video. (In HD, if you can, so ...