Today went live on euro servers the last patch for World of Warcraft, 5.0.4, which sets scene for the changes coming with the imminent expansion, Mist of Pandaria. This update makes lots of changes, notably to the talent trees which were completely removed and replaced by a much more simple talent system (dare i say, bad?), shared achievements, pets and mounts, cross-realm zones and other improvements and/or changes.
On a personal opinion, i find the change on the talents to be quite a letdown. I really don't see it being any fun, having just a new talent choice every 15 levels... Besides that, players will only get new spells per level, no more new talents. The only thing i like, is the ability to use, otherwise specific talents, independently of what gear you want to use (example, wielding two two-handed swords as dual wield and do bladestorm).
In any case, more details about this update can be read here.