George just LOVES recurring themes (IE - hasn't had an original thought in 30 years).
Episode III will feature a prototype Death Star superlaser. This prototype will test its destructive power on Amidala's home planet of Naboo. It won't work to Sidious's expectations, simply destroying all humanoid life. He goes to the designers and demands something that completely reduces the planet to space debris.
The destruction of "Naboo" accomplishes a lot in a short period of time:
- demonstrates the Sith's ruthlessly evil intent
- kills Padme and Jar Jar and the remaining Jedi
- creates a new setting of volcanic ruin for Anakin to battle Kenobi ("This is YOUR fault!")
- echoes Kenobi's sense of death vs. change ("...from a certain point of view."

)
- explains why Dagobah is such a center of darkness
- gives Yoda a great hiding place