A moment ago Vittorio Bertocci wrote a post on some upcoming changes to the Developer Preview of WAAD. The changes are of the breaking sort, so if you're actively using WAAD, this is something you'll want to react to.
The WAAD MSDN forums have a more detailed announcement about the changes, but at a glance, here are the two key things I picked up on.
Your (most likely automatically generated) Web.config settings say something like this now:
<wsFederation passiveRedirectEnabled="true" issuer="https://accounts.accesscontrol.windows.net/tenant-id/v2/wsfederation" .... requireHttps="false" />
After the change, that will have to change to:
<wsFederation passiveRedirectEnabled="true" issuer="https://login.windows.net/tenant-id/wsfed" .... requireHttps="false" />
The metadata and JWT endpoints are changing too, which may or may not affect you -- but if you're using any of them, you'll probably know what to do anyway. :-)
A while back, the claim that actually names the user principal was changed from EmailAddress to UPN. Now things are changing again, and in the future, the naming claim type will be ... name! Which means your web.config settings need to change from
<nameClaimType value="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/upn" />
<nameClaimType value="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/name" />
That's pretty much it. And of course, if you can't get the settings right editing them by hand, you can always run the Visual Studio Wizard again.
Hope this helps someone. :-)