I'm not sure exactly where I saw that DRAC6 Express does not do console redirection -- it was on a mailing list somewhere -- but that turns out to be just wrong:
(For the record, it was the "External Serial Connector" in BIOS that got me; it should be "serial device 1", not "Remote Access Device".)
I can now SSH to the DRAC and get a console just fine. I wish to apologize to Dell, the people of Monaco and the constellation Sagitarrius.