iTunes 9.0 has a new look, and according to Steve Jobs, "We cleaned it up quite a bit and made it much easier to navigate around." He touted the "Genius" database, where now it's more powerful and able to determine which songs go well together.
Also, as we had hoped, it lets you manage apps inside iTunes. At the same time, the iTunes store has what jobs called "cleaner navigation," and also offers individual pages for artists, TV shows and movies. In addition, there is the ability to share media around the home, letting you copy TV shows and movies to five other PCs.