In the mean time I created a blueprint extension for authorization based on JAAS and Java EE annoations (@RolesAllowed, @PermitAll, @DenyAll). You can add the extension to any blueprint file. It will then scan all beans for these annoations and intercept calls if they are found. It uses an existing JAAS context to get the roles of the user.
So prerequisite for this is doing a JAAS login. I have also created a CXF JAASAuthentication feature that logs in a user based on basic auth or ws security username principal. The module works together with the Apache Karaf JAAS support. So all karaf users and roles apply.
I will create a tutorial to show how to use all of this once the aries blueprint release that includes the authorization module is out. In the mean time I would be happy if you try it out and report any problems you have.
Btw. another approach for karaf is the role based access control for OSGi services that is built into karaf 3+. It does not work with annotations but is also easy to use. See
http://coderthoughts.blogspot.de/2013/10/role-based-access-control-for-karaf.html