The OP does a service by providing a link for formal comments, but it's not as if bad practices are limited to Delta. Here's a list of DOT's Aviation Consumer Protection Division enforcement orders over the last year:

Enforcement Orders

COPA Airlines, disability reporting 2010-07-15
Delta Air Lines and Northwest Airlines, codeshare disclosure 2010-07-04
Sceptre Tours 2010-06-28
Cayman Airways 2010-06-21
Mercy Flights 2010-06-18
FarePortal 2010-05-31
Delta Airlines 2010-05-30
AirTran Airways 2010-05-29
Falcon Air 2010-05-15
Continental Airlines 2010-05-09
RM Aviation 2010-05-01
Aero Services 2010-04-17
Southwest Airlines 2010-04-14
Bahamas Air 2010-02-27
Luxury Air Jets 2010-02-17
Myrtle Beach Direct Air & Tours 2010-02-16
United Airlines Inc. 2010-01-13
TAM Linhas Aereas 2010-01-08
Canadian Helicopters Limited 2009-09-10
Spirit Airlines 2009-09-08
Costa Cruise Lines 2009-09-03
United Air Lines 2009-08-17
Quebec d/b/a Univair Aviation 2009-08-12
Hawaiian Airlines, Inc. 2009-08-04
Continental Airlines, Inc. 2009-08-03
U.S. Airways, Inc. 2009-08-02

For the details, http://airconsumer.ost.dot.gov/rules/consentorders.htm