Will the login functionality built into the Users API stop working on April 20th?

I am currently using the Users API (this one here) with the Go language on my Google App Engine application. My users are getting the warning message when they first grant permissions that says "OpenID 2.0 for Google accounts is going away. Developers should migrate to OpenID Connect by April 20, 2015." But I can't find any warnings in the documentation for the Users API anywhere saying that anything will stop working, like I do all throughout other sections regarding OpenID 2.0 (here).

I am using very little of the Users API code, just to create the login urls like this:

url, _ := user.LoginURLFederated(c, return_url, "www.google.com/accounts/o8/id")

And to read the users' email addresses, like this:

u := user.Current(appengine.NewContext(r))
email := u.Email

Do I need to worry about migrating, or will the Users API handle everything without failing after April 20th?

Please read this information:
https://developers.google.com/identity/protocols/OpenID2Migration
https://developers.google.com/identity/protocols/OpenIDConnect
https://developers.google.com/identity/sign-in/auth-migration

You may also find this forum post helpful.

Apps that use user.LoginURLFederated in conjunction with Google Accounts will stop working. These apps need to follow the information in the first link above to migrate.

Apps can continue to use user.LoginURLFederated for use with various other third-party OpenID2 service providers.

So, it turns out that the answer is "YES!". Definitely stopped working. The older development versions of my website now take you to an error page when you try to sign in. Luckily I had moved away from the User package before the deadline to the much buggier Google Sign-In for Websites.