Gotta love Homesharing, though I didn't utilize it when I made the switch. My old PC wouldn't allow it thanks to it not connecting to the network I have at home. I ended up grabbing my entire iTunes library folder (everything-music, video, iPod settings, iPod touch/iPhone backups etc. I mean everything- though I forgot where exactly it is located) and storing it on an external hard drive.
But yes, iTunes 9 has that beautiful little thing called Homesharing.