The one thing I like about the Chrome Web Store is that it seems that security is at its heart. The permissions that each installed app needs are presented in easy to understand language, which makes it very convenient when installing applications or extensions.

This FAQ breaks down the permissions and their definitions:
http://www.google.com/support/chrome...er=186213&rd=1

This takes a lot of guess work out of installing apps, and producing complex relationships between services.