Business Catalyst is doing the email upgrades as I type, and you can now update your password.
login to your administrator access to your site. This is also available here:
Next, you should see this message at the top of your log in screen:
(Click Image for Full Size)
then you can follow the instructions in yesterday's blog post to complete your password update.
If you are an 'Email Only' user, there are also instructions there for you.