One of the features in this service pack is the KerberosToken2 token. I previously worked on a custom binary token that passes Kerberos tickets over the wire. The great news is that the KerberosToken2 token in WSE 2.0 SP2 enables you to obtain user-level authentication tickets as well as encyption and signatures based on the Kerberos ticket. This relieves you of maintaining custom security code and distributing to client machines.
Thanks, Hervey! I know just the customer that will put this to use.