In building a lot of custom workflows, I've found that the ability to send an email to all users of a role would be useful, so here's a patch against 6.x-1.11 which provides a new "Send a tokenized email to users of a role..." action. It's got fairly robust error checking.
FAILED: [[SimpleTest]]: [MySQL] Invalid patch format in new_role_email_action6.patch. View
PASSED: [[SimpleTest]]: [MySQL] 31 pass(es). View