It appears that the function delete_on_termination will only return the bool value and does not allow one to set it.
I have not confirmed but it appears this can only be set via the SOAP API which the ec2-modify-instance-attribute uses when making this call:
ec2-modify-instance-attribute -b =:
I have the SOAP request and could simply write my own method to make this change but it would be far simpler to have it implemented in boto.
Is anyone interested in developing this feature?
Allow DeleteOnTermination to be changed via ModifyInstanceAttribute
closes #542 and probably #820