with American
 

I think Dividend Miles is really cool. They got American Express back as a partner and with this new American deal, who needs BA? Although, having said that it looks like we'll have BA back since they are partners with American. Might this be the (B)ack (A)gain Alliance?

A spokesperson for US Airways refused to speculate on whether a link up with British Airways was possible. If indeed an alliance does materialise it will prove that the airlines involved have the memories of goldfish. It was only last March that US Airways announced it had expanded its lawsuit against British Airways for violating provisions of its 1993 alliance agreement with US Airways.
The proposed partnership between American Airlines and US Airways is purely a marketing agreement. Frequent flyers will be able to combine miles from both programs to redeem awards on either airline. All going well the proposed partnership will come into effect late summer.

What will it mean "members can combine" AA Miles and Div Miles? Is a DM worth an AA Mile?

Essentially yes, members who belong to both American AAdvantage and US Airways Dividend Miles will be able to combine miles from both to claim awards for travel on either airline. AAdvantage members will be able to use their miles to claim awards on US Airways and vice versa. Members will not be able to claim partner airline award flights. US Airways Dividend Miles members will be especially pleased to have the option of award flights to Hawaii.