Given the discussion at http://dev.opencascade.org/index.php?q=node/30, especially following the remark from Roman and Thomas about the perpetual nature of the CLA, we plan to provide users with a procedure for terminating a CLA. This would be done by sending a request to us, like you can do for terminating your account.
The entire process will be described in the http://dev.opencascade.org/?q=home/get_involved/cla_processing_rules page.
Naturally, the CLA will be updated accordingly.
This evolution should be published hopefully next week.