I just wrote a very little tool that can import CSV files exported from Lastpass into the Mac OS X Keychain so they can be used by Safari to fill forms. This may be useful for people who want to switch from Lastpass to iCloud Keychain (or use it in addition to Lastpass) once it’s available ( http://www.apple.com/de/osx/preview/#icloud-keychain )
The tool is very simple and dumb. It does not check if an entry already exists, but will just create a new one. Also I think Safari currently can’t handle multiple accounts per site, so if you import CSVs with multiple accounts for a site, only one will be used in Safari.
Maybe I’ll add some sort of sync functionality to the tool in the future.