Email addresses for usernames in 3.4 multisite?

In order to work well with out LDAP/AD setup, we need to use email addresses as usernames. To do this in the past, we’ve been manually changing the username in the WP database – which is a pain, but works.

I was recently setting up a local test install of 3.4, and during registration I noticed this when choosing the admin username:

Usernames can have only alphanumeric characters, spaces, underscores, hyphens, periods and the @ symbol

See here for an example: http://siteuntitled.com/images/info-needed-anon.png

After seeing this, I used an email address to create the admin user and it worked fine. I then went to the dashboard and I was also able to create another user with an email address there too!

I thought this must mean that email addresses could finally be used as usernames in WordPress, but my excitement was short lived. Our sites are managed in a network using the multisite mode. I then setup a network on the test install and tried to add another user with an email address username – and I got the usual error:

Only lowercase letters (a-z) and numbers are allowed.

So, does anyone know if it is possible to enable email addresses for usernames in multisite – or is this allowed for a single blog setup only?

Thanks!