Update: A segment about Ellen's visit to Deal or no Deal aired on her show today and she wore a dress!
Here's the video

I can't wait to see the whole episode of Deal or No Deal!

-------------------- Original post from 10-29-2007 -----------------
Ellen will be on of the 26 brief case models on Deal Or No Deal scheduled to air in January of 2008. 

"Ellen is a great supporter of the show and we were looking for our first celebrity model. Who better to do that than Ellen?" says Libby Hansen,

It's not clear whether or not Ellen will wear a dress (I doubt she will) but she has a agreed to be one of the models and she knows that they wear dresses.

Will DeGeneres really wear a dress? "Ellen knows our show and knows the kind of sparkly, sequined dresses our spokesmodels wear, and she's agreed to be [one of them]," Hansen says a bit cryptically. "Ellen won't do anything she’s not comfortable with." Then again, Hansen says, "Who doesn’t want to see Ellen in a dress?"

Ellen will bring a camera crew with her to film a segment that will air in late November.

Source: TVguide.com