Bind Relaying Party to Identity Provider

ADFS 3.0 improves user experience With a long wanted feature:

Improved user experience for home realm discovery –AD FS now supports home realm discovery by looking up organizational account suffixes that a claims provider supports or by looking up the claims provider list that is configured for a relying party trust. AD FS also supports by-passing home realm discovery for intranet Access.

Source: http://technet.microsoft.com/en-us/library/dn280950.aspx

This means you no longer need to manually choose which Identity Provider to use when you have different Identity Providers based on different Trusted Relaying Parties by configuring a specific Identity/Claims Provider for a specific relying party trust.

You can also lookup a specific UPN-Suffix and configure that for a specific Identity Provider. Meaning some users can use Active Directory as Identity Provider and others can use other configured Identity providers.