Today you’ll notice that our traditional sign in form:
has been replaced with a Sign in with WordPress.com button:
This change is much less dramatic than it sounds, because VaultPress.com already uses WordPress.com for user accounts. What Sign in with WordPress.com does is formalize the relationship between your WordPress.com and your VaultPress.com accounts.
Let’s walk through what happens when you click the Sign in with WordPress.com button for the first time:
When you click the sign in button you’ll get a log in form for WordPress.com:
Existing VaultPress users will enter their usual VaultPress password and email address to log in. The Forgot your password link is there if you need to reset your password.
Once you’re successfully logged in you’ll see the authorization page:
Simply click on Authorize and we’ll redirect you back to VaultPress.com, where you’ll be logged in and able to access your account information.
As always, if you have any questions please don’t hesitate to contact us.
VaultPress Blog 
What benefit does a customer who does not use wordPress.com gain from using the new login process. The customer uses a “self hosted” version of WordPress.
It will make it easier to use multiple Automattic services under a single account. There are other features planned for this single sign-on ability via WordPress.com as well.
Important to keep in mind that VaultPress.com accounts were already backed by WordPress.com, so the change for VaultPress users is very minimal.