You can open a JIRA issue and suggest it. In the meantime, remember that you can install your own subclass of identity that has exactly the behavior you want.
Just override the login message, set it to null if you don't want to display it. The seamspace example demonstrates how to do this.
Also note that if you are using roles then there is a bug that doesn't clear them down when Identity.login is performed. This is fixed in CVS but not (as I am aware) in any release version. I think someone should make this more widely known as there is a workaround for it and it could compromise security.
Overriding the message work fine.
So I guess there is no need for a JIRA issue.
Thanks a lot.