It takes only a minute to pull it from delta.com (it's just that most people don't read the fare rules and don't know what they are getting; I do and always save it for all bookings - you never know when you'll need it, and that is right where it is, under fare rules when booking non-DL flights), and it was about time for me to update my own .txt file on this anyway, so here you go, this is the current blackout dates as of today.

GENERAL RULES TEXT

***KE****
IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY KE FLIGHT OR IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY KE FLIGHT IN COMBINATION WITH ONE OR MORE OF THE FOLLOWING ANY 9W FLIGHT ANY AF FLIGHT ANY AM FLIGHT ANY AS FLIGHT ANY AV FLIGHT ANY AZ FLIGHT ANY CI FLIGHT ANY CZ FLIGHT ANY DL FLIGHT ANY HA FLIGHT ANY IT FLIGHT ANY KE FLIGHT ANY KL FLIGHT ANY KQ FLIGHT ANY MH FLIGHT ANY MU FLIGHT ANY OK FLIGHT ANY SU FLIGHT ANY TN FLIGHT ANY UX FLIGHT ANY VA FLIGHT ANY RO FLIGHT ANY VN FLIGHT ANY G3 FLIGHT TRAVEL IS NOT PERMITTED 05MAY 11 THROUGH 10MAY 11 OR 20MAY 11 THROUGH 03JUL 11 OR 16JUL 11 THROUGH 28AUG 11 OR 10SEP 11 THROUGH 14SEP 11 OR 01OCT 11 THROUGH 03OCT 11 OR 09DEC 11 THROUGH 31DEC 11 OR 01JAN 12 THROUGH 08JAN 12 OR 20JAN 12 THROUGH 25JAN 12 OR 01MAR 12 THROUGH 04MAR 12 OR 04MAY 12 THROUGH 06MAY 12 OR 18MAY 12 THROUGH 01JUL 12 OR 14JUL 12 THROUGH 26AUG 12 OR 28SEP 12 THROUGH 03OCT 12 OR 07DEC 12 THROUGH 31DEC 12.

***CI****
IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY CI FLIGHT OR IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY CI FLIGHT IN COMBINATION WITH ONE OR MORE OF THE FOLLOWING ANY 9W FLIGHT ANY AF FLIGHT ANY AM FLIGHT ANY AS FLIGHT ANY AV FLIGHT ANY AZ FLIGHT ANY CI FLIGHT ANY CZ FLIGHT ANY DL FLIGHT ANY HA FLIGHT ANY IT FLIGHT ANY KE FLIGHT ANY KL FLIGHT ANY KQ FLIGHT ANY MH FLIGHT ANY MU FLIGHT ANY OK FLIGHT ANY SU FLIGHT ANY TN FLIGHT ANY UX FLIGHT ANY VA FLIGHT ANY RO FLIGHT ANY VN FLIGHT ANY G3 FLIGHT TRAVEL IS NOT PERMITTED 01JUN 11 THROUGH 31AUG 11 OR 10DEC 11 THROUGH 31DEC 11 OR 01JAN 12 THROUGH 04JAN 12 OR 16JAN 12 THROUGH 26JAN 12 OR 01JUN 12 THROUGH 31AUG 12 OR 10DEC 12 THROUGH 31DEC 12 OR 01JAN 13 THROUGH 04JAN 13.

***MU***
IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY MU FLIGHT OR IF THE FARE COMPONENT IS ON ONE OR MORE OF THE FOLLOWING ANY MU FLIGHT IN COMBINATION WITH ONE OR MORE OF THE FOLLOWING ANY 9W FLIGHT ANY AF FLIGHT ANY AM FLIGHT ANY AS FLIGHT ANY AV FLIGHT ANY AZ FLIGHT ANY CI FLIGHT ANY CZ FLIGHT ANY DL FLIGHT ANY HA FLIGHT ANY IT FLIGHT ANY KE FLIGHT ANY KL FLIGHT ANY KQ FLIGHT ANY MH FLIGHT ANY MU FLIGHT ANY OK FLIGHT ANY SU FLIGHT ANY TN FLIGHT ANY UX FLIGHT ANY VA FLIGHT ANY RO FLIGHT ANY VN FLIGHT ANY G3 FLIGHT TRAVEL IS NOT PERMITTED ON 29APR 11 OR ON 03MAY 11 OR 10SEP 11 THROUGH 11SEP 11 OR ON 13SEP 11 OR ON 15SEP 11 OR ON 26SEP 11 OR 29SEP 11 THROUGH 04OCT 11 OR 06OCT 11 THROUGH 08OCT 11.

Still only KE, CI and MU - no other airlines have any blackout dates. For MU the blackout dates only go to Oct 8, 2011 and no further. It seems as if perhaps as of this October 9th MU will no longer have blackout dates..or simply they have so few, and that ones for next year don't start until May (now it should be published only up 330 days ahead), and they haven't yet published 2012 ones. So, now is a good time to book MU flights for 2012, as at this time no blackout dates, and they may impose some later (though still for MU it's usually just a day or two blacked out, really short periods, so it's quite easy to work around it if you are even a bit flexible).