It seems like Microsoft has confirmed the release dates for Windows Live Wave 4 web services to be in early June 2010 following an email sent to Microsoft Live@edu administrators about upcoming co-branding changes to Windows Live services. Here’s an excerpt from the email:

As part of the upcoming Windows Live June release, new co-branding options will appear on May 10 in the co-branding user interface of the Windows Live Admin Center. Please familiarize yourself with the changes outlined in this e-mail to be aware of important limitations to editing your co-branding from May 10–June 1.

Due to the release of the next iteration of Windows Live in early June, the ability to edit co-branding of the current versions of Windows Live services will be locked on May 10. Any changes you make to your co-branding beginning on this date will not appear until the June release versions of the services are available.

As each Windows Live service is updated for the June release, end users will see any new co-branding changes made after May 10. However, until a service has been updated, the end user will continue to see the same co-branding they see today. Please note that the next versions of Windows Live services will be rolled out over a period of months, which means that some end users could be on the old version of a service while others could be on the new version.

Note that this roll-out schedule applies to Windows Live (web) services only, and to put the words “over a period of months” in context, we suspect that this probably applies to Windows Live Hotmail (and Contacts) only, consistent with what we have experienced in the past few Hotmail update roll-outs. For Windows Live Essentials, we’ve heard words that the public beta release date is June 21 (according to Microsoft France). Seems like we’re getting closer to the date when we can finally get our hands on Windows Live Wave 4!

Thanks to Rahadyan for the tip!