My concern with the concept of "password strength" approaches is that it often encourage passwords that are harder to remember (e.g. forcing the user to use caps underscores, etc.).
The shared approach tries to visualise both how strong and whether you typed the correct password (by displaying always the same colours given a specific password). The last part was something similar to what the old Lotus Notes did by displaying different icons of keys next to the password field. That could be slightly useful to anticipate errors but have an impact of initial confusion until the user understands what it is about.
Pau