I am currently writing a plugin to allow customization of the preset roles. Its goal is to allow the administrator(s) to issue/withdraw capabilities to specific roles (exception: the Administrator role, for -- at least for me -- obvious reasons). This of course will be exclusive to WP 2.0 "Duke".
Anyone who would be interested in testing it can e-mail me at:
jcraveiro -aaattt- jcraveiro -dddooottt- com (please start your subject with [WPRM])
and I will contact you as soon as I have a first test release ready.