The recent announcement that Seth Rogen and Elizabeth Banks are set to join Kevin Smith's "Zack and Miri Make a Porno" may give us at MTV one more reason to count our blessings -- just one week after we named Rogen the [article id="1574554"]actor we're most thankful for in 2007[/article].

OK, make that two reasons.

"You might see my ass again," Rogen joked of his role as Zack in the upcoming Smith comedy, which centers on a pair of twentysomethings who decide to shoot an amateur porn film to make money. "Am I working up to [frontal nudity]? I don't know."

"We definitely have a shot [like that] in this movie," Smith laughed. "It's not his, but if he wants to try to upstage what we'll see onscreen, that'd be awesome!"

It's all laughs these days for Smith now that he's landed two fast-rising stars for the roles of Zack and Miri. Rogen's casting in particular is especially gratifying, the director admitted, considering he wrote the titular role specifically for the "Knocked Up" star -- and then spent an entire summer worried he wouldn't get him.

"After 'Knocked Up' came out, I was like, 'Ugh, he's on to bigger and better things,' " Smith said of Rogen's rise to fame. "I figured we were kind of dead in the water, but patience and perseverance prevailed, and he came onboard. It was stunning but wonderful.

"From the moment that dude started talking in '40-Year-Old Virgin' about watching a horse show, I was like, 'Oh, this guy's fantastic,' " Smith continued, gushing. "I just loved his delivery. [I thought] he would fit in the world of what we do very well."

For Rogen, fresh off his very successful summer, entering Smith's View Askewniverse seemed a natural transition.

"I feel like my strengths were always kind of ripping off a Kevin Smith movie anyway. It's not a far departure," Rogen said. "I read it and I loved it. It's very, very raunchy but with a sweet twist to it. It's very much in the style of the movies we've been doing but brought to a whole new level of filth. It's just a really great script."

While Smith hounded Rogen, Banks (another "40-Year-Old Virgin" scene-stealer) came to the project only after Rosario Dawson, [article id="1565058"]for whom the director originally wrote the role of Miri[/article], backed out of the project to film "Eagle Eye" for producer Steven Spielberg. But Smith couldn't be happier with how the casting turned out.

"If Rosario had stayed in, I wouldn't have thought past her, but when she took the Spielberg movie, suddenly it was like, 'All right, where do we go?' " Smith recalled of what led him to Banks. "That kind of left us wide open and, oddly enough, casting Banks turned out to be this insanely genius move. I haven't seen one negative reaction to it. Online, people are going, 'Yes, finally she's getting a role like this.' "

According to Smith, it's not hard to see why.

"If you see her stuff with David Wain and the 'Stella' guys, if you've seen her in 'Wet Hot American Summer,' you know she's f---ing funny," Smith said. "It's not very often that you find a woman who's as pretty as Elizabeth who can also be funny and just kind of take the piss out of herself."

As a lecturer, blogger and frequent interview subject, Smith is known for being remarkably candid and open about his upcoming projects. But now that he's got his two principal stars for "Zack and Miri," the director told MTV News that he's ready to clam up a little, momentarily falling short of fan expectations -- so he can subvert them later.

"What's kind of daunting about the flick is because of the title, people know more about it already than they have about most of the stuff I've done in the past -- or at least think they do," Smith said. "They have a movie in their head, but the one in my head is probably different than theirs. I mean, can you believe there's not one fluffer joke in the entire movie?"

One of the additional burdens of including "Make a Porno" in the title of a movie, Smith laughed, is the characters who suddenly come to his aid, claiming expertise.

"There have been a lot of people who have come out of the woodwork from the adult-film industry to offer their help," Smith said. "But the movie's not really about the adult-film industry. Yes, the word 'porno' is in the title and, yes, they are trying to make a porno -- but these are rank amateurs."

"I did my research for that with 'Clerks,' " Smith added, so don't expect him to do any additional studying.

"When you're married, you don't take that call," he deadpanned. "You're already pushing it when you tell your wife it's called 'Zack and Miri Make a Porno.' "

Smith, Rogen and Banks start making their "Porno" January 16.

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