A considerable change to Safari 5.2 on the Mountain Lion developer build seems to be that of a new pane that allows you to view and remove stored passwords, MacRumors reports. This could be quite similar to the 1Password service, which allows you to have one master password for everything.
The text string describing the application reads:
Safari can automatically suggest and remember unique, secure passwords for websites you choose.
This does suggest something more advanced than just a password database service however, so we could be seeing some more advanced password options built into Safari in the near future.