I've been having trouble now with dead class assignments and it would be nice if Foreman could report them.

Example 1:
Situation: "Node1" in environment "production" has a class NTP assigned to it. In Foreman you change the environment to "test" where NTP is not present. Foreman keeps NTP on the left side as an assigned class without any warnings.
To make it worse, puppet completely ignores missing classes for external nodes as you can see here:

http://groups.google.com/group/puppet-users/browse_thread/thread/79d8274ec5ad256e?fwc=1

Example 2:
Situation: The NTP class is renamed or deleted. Some nodes that use this class will have now an "orphan" assignment but you are not able to detect that. Puppet won't tell you (as seen in the link above), and Foreman also won't tell you this (even after a rake task to import the classes).