They seem to be similar on the surface, but I'm not sure how deep the differences are.
Can someone explain to me the difference between SAMLp and WS-Trust? ADFSv2 gives me a choice between these options and I'm not sure which to choose.
WSTrust is a standard which is specifies how to encrypt/decrypt/sign SOAP messages and how to bind security tokens to a SOAP message.
SAML tokens are an example of a security token that could be bound to a SOAP message.
The SAML protocol provides a standard way to acquire, release and renew SAML tokens using SSL to protect communications and the XmlDsig standard to protect the token.
AFAIK, They are similar WRT the end-goal.