Will WSE or Indigo ever support SAML?
According to Benjamin Mitchell's post from a TechEd Don Box Service Orientation presentation, we don't know when or if SAML will be directly supported:
WS-Security vs. SAML?
There are many different kinds of tokens that may be used, such as Username, X509 certificates and Kerberos tokens. Don said it was unlikely that a token type, like SAML will become the 'single token format to rule them all'. No definite answer on where the SAML support was. As I learnt on Saturday, trying to implement SAML support is a non-trivial exercise - it would be nice if there was a clear statement from Microsoft on when it will be supported in the platform (so that you don't have to share my dll in order for us to use it when we talk). I think it will be part of the identity management work in future.
Michele Leroux Bustamante's very philosophical post on the same talk elucidates the "Saturday" comment: She and Benjamin wrote a sample SAML implementation, So Benjamin ought to know.
Here's his post before the presentation.