The people to follow are not a representative choice but those I know and who have a good web presence. If you want to be listed here drop me a mail.
Ali
Arsanjani does research on rules and rule systems and has also been the organizer of
an OOPSLA 2000 Workshop on Business Rules
Jens
Coldewey: does consulting on product servers
Ralph
Johnson used to be interested in building insurance software, mostly using
Smalltalk. He still does useful stuff for the domain, e.g. the Accounts
framework and also the User
Defined Products framework. He did this work together with Jeff
Oakes.
Wolfgang
Keller: operates this site and is an architect at
AMB Generali Informatik
Joe
Yoder (who also does database
access layers) is another organizer of the OOPSLA
workshop on Business Rules
Lubor
Sesera from softec Bratislava has also written patterns in the insurance domain (Recurring
Duties Analysis Pattern)