None of these is supported or planned yet. Integration with both can be build.
Could you give an update on SAML? Did you build this or has this never got of the ground? At Daywize we might need this also, and would rather reuse something already build then start from scratch.
This never came of ground, initially we wanted to use SSO for integration with social apps like a forum, blog, q&a using a popular e-commerce framework. However we found a solution to have a community environment, we used commons . Implementing SSO was not needed anymore, but we are still interested for future projects to build a better eco-system when using Mendix with multiple frameworks. However, being specific I can't help you any further if you want to integrate Mendix with it. Keep me updated! :)