While it is true that Triple Threats are No DQ, by default, adding the hardcore stipulation makes it clear that this match will feature a lot of hardcore spots. And, really, this is the best way for Dreamer to look good. Dreamer does two things well - get his ass kicked, and hurt people with weapons. This match lets him do both. He'll get his ass kicked by Swagger for a while, and later in the match he'll beat the shit out of both of them with chairs and canes and what have you. He'll also do his silly ECW baseball slide, but now, into a trashcan. What fun!
Dreamer's going to win. Of course he's going to win. He puts out his mandate, he says he's signed a one day contract extension, he's an ECW legend (kind of), and it's the ECW PPV. What more could scream "Dreamer wins, Dreamer wins"? Christian will probably take the pin, because he can afford to - Dreamer will look like a somewhat respectable champion by pinning the champ, and Swagger won't have to lose to an old guy. Christian is already so well established he can take the pin, and no one will care.
Dreamer will go on from here to defend a few times - I think he'll make it two months, until Night of Champions (which is in Philadelphia), retain there, and lose on ECW or Superstars at some point after. Maybe if he's really lucky, he'll get to SummerSlam to drop to Bourne or Koslov.
It should be a solid match - Christian can do hardcore well, Dreamer obviously can, and Swagger can probably pull out a few nice tricks as well. I fully expect a Dreamer title win.