Apple has quietly released Bonjour Update 2010-001 via Software Update, saying only that "This update improves the reliability of connections between iTunes and Apple TV." Previously known as Rendezvous, Bonjour is Apple's implementation of the Zeroconf protocol for discovering network services. Oddly, Bonjour Update 2010-001 hasn't yet appeared on the Apple Support Downloads page. (Free, 959K)
View Extra Audio Details in Snow Leopard
In Snow Leopard, Option-clicking the Volume icon in the menu bar displays a list of sound input and output devices. Choose one to switch to it; it's much easier than using the Sound preference pane. Also, hold Shift and click the icon to set the system volume, which is separate from the general output volume.