The fight between SAML 2.0 and WS-Federation has been present in Danish eGovernment for some time, and here the choice has fallen on SAML 2.0, being an OASIS standard with a fair product support. There's more background information on that on Denmarks choice of SAML as the federation standard.
Newly the Danish National IT and Telecom Agency (DNITA) has announced an agreement with Microsoft about partial support for SAML 2.0. The central part of the quote from the agreement is:
To support interoperability between WS-Federation and SAML 2.0 based products Microsoft has agreed to support the SAML 2.0 token format in the future release of Active Directory Federation Services code-named Active Directory Federation Services2.
So it's only the Token format and it's not until the next version of ADFS, but god news is always welcome. It also mentions that WS-Federation has recently been submitted to OASIS, and adds:
This step further enables interoperability between federated environments that deploy SAML 2.0-based products and those that deploy WS-Federation-based products.
Well I'll say the jury is still out on that one as I've touch on in Federation power fight in the backyard of OASIS. As for the prior fight between SAML 2.0 and WS-Federation, I've found some articles like Microsoft Backs Web Services-Federation Against SAML 2.0 For Identity Federation and Vendors team on WS-Federation standard