Buying individual components will lend itself to future expansion and leave you with an open system to expand with newer compnents in the future. This will give the system a longer life and greater satisfaction.
I am trying to decide whether to spend $600 on the new Sony BDV-E300 Blu-Ray Home Theater System, which pretty much comes with everything that I need, or spending anywhere from a $1000 to $1500 building a system by purchasing a separate receiver, Blu-Ray player, and speakers. I have a Sony XBR9 HDTV and the new Sony E-300 is just being released. Everything is telling me that this is the way to go. Am I wrong? Input from people with knowledge in this area is greatly appreciated.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic