I got a notice form Orbitz that Delta intends to charge $25 for second checked bag beginning May 1.

That is new news. I'll ask tomorrow when I check in.

That is old news. From delta Website:

Checked Baggage
Currently, you can check two bags per passenger free of charge. Starting May 5, 2008 this will be reduced to one free bag per passenger traveling in the U. S., the U.S. Virgin Islands, and Puerto Rico.

Each bag must:

Weigh 50 pounds (22.5 kg) or less.
Not exceed 62 inches when you total length plus width plus height.
If you have a bag that exceeds these allowances, see Excess Baggage.

Exceptions:

Business Elite® and First Class passengers are allowed 3 checked bags at no charge up to 70 lbs.
Passengers traveling to or from Key West and Marathon, Florida are limited to only one checked bag.
The free weight allowance is 70 pounds (32 kg) for tickets purchased in Brazil, or for tickets purchased in Japan when traveling to/from Brazil.
Active duty military personnel with traveling orders will be allowed to check 2 bags up to 70lbs at no additional charge.
With the exception of original factory-sealed boxes that will be accepted on a standby basis, we do not accept boxes as checked baggage to Central or South America (except Brazil, Mexico, and Chile) at any time of the year.

Some packages, sporting goods, musical instruments, and fragile or bulky items may require special handling. For more information on special items, see Special Baggage.

I spoke with a Delta representative today and pretty much what tradwinds stated I was also told. It looks as though the 2nd baggage charge will be for travel within the U.S., unless flying First Class, Business Class or a Medallion member. If flying internationally, the 2 bag rules still apply.