Generally speaking, if they delay a game, it probably won't be World of Warcraft (See: Starcraft 2). However, it will be released when it's ready to be released like Scott said. The Beta still seems pretty early in development, but things can move so fast at times, it's hard to tell. The internal build that the Devs have is always 1-2 builds ahead of what we see, so mass changes might just happen all at once one day. They seem to be into a different phase on the talent system at the moment. They're not really just creating new talents anymore, they're nitpicking at them and making sure the choices you have just "feel" right. After that you just have new content, professions, and guild stuff to handle... then numbers. We'll see how it ends up!
On another subject, the login music is a very nice change of pace. I love the new login screen music... although I still hear the original one with my beta client. Either way, it's badass!
"Kyle, this is the way the world works. If you want to find quality friends, you have to wade through all the dicks first." -Cartman