In Remove Alternative openID it is said that this feature will be included in next SO deployment. So, how often are new SO versions deployed?
Unless it's an odd week (when the team is at MIX, or holidays for example) we're usually building every day, and often several times a day. To be accurate, we're probably even building then, since we're all a bit insane.
As a general rule, we don't build during peak traffic. We try to cause as little interruption as possible. If there's a high-impact bug or change that needs to be fixed/made, we'll make an exception.