I hope that if they actually release regular Marik (honestly, I couldn't care less either way) they give him something that sets him apart from Ishizu, Odion and Yami Marik. I don't know HOW, but if he just gets a couple of leftover Gravekeepers and Fiends, he'll feel like even more of a wasted character.
Honestly, a different character. I can't think of how they'd make his inclusion worthwhile from a card standpoint. There isn't an obvious archetype like Ishizu's Gravekeepers or Bastion's Chemicritters to pad out his cards, either, and most of his cards are already Yami Marik drops/level rewards or in packs. Can't really have a cardpool based around just Metal Reflect Slime and Granadora...
On the Leaked Information page, they show Marik (not Jaden anymore) having all of these skills for the Winged Dragon of Ra. I don't know if I'm interested in using that, though. Ultimately, I don't care what he has as long as he comes to the game, but I can understand how he doesn't look too exciting as a duelist. Zane looks more fun with his Cyber Dragon stuff.