1) one of the reasons I use a password store is to share passwords with my wife. I can't imagine her using this 2) iPhone? Android? 3) 1password's integration with the browser is very helpful: since I've been using a linux box as my day-to-day machine (where 1password doesn't have a native version), I've been using it significantly less, because it adds friction. On Mac OS, I would just auto-gen a horrific 12-16 character random password for any website, and have it automatically saved to my 1password.
As you might guess, I have high hopes for Mitro, especially if they (well, I guess it's now we) can create a compelling don't-use-their-host story (either hosted, or file-based (eg. dropbox)) and pass at least a cursory security smoke test. :-)