Any iStock exclusive who also sells RM at Alamy might be interested in a recent development at Alamy which might compromise your position. I feel it's more an Alamy issue, so posted the details there rather than here.
http://www.microstockgroup.com/alamy-com/alamy-premium-rm-as-rf/msg212264/?topicseen#new
and humbly suggest discussion, if any, should be there to keep just one thread.
Added: I now see that the proposed new license is not RF, but a very wide RM license - use within the purchasing company, 10 year time limit, no advertising. So that shouldn't impact on IS exclusivity.