@Radical:
I kinda like this no parent thing. it would be dumb if every one of the strawhat's parents were a admiral/Shichibukai/yonkou/pirateking/important plot device.
Though I agree with wouldn't be that GREAT if all the Straw Hats had powerhouse parents, it's possible something could come up as a plot device.
Case in point? Since there's been a lot of focus on him already, if it's discovered one of Sanji's parents, not Zeff, was the root of his chivalry, then that would be a a minor plot point explaining a huge part of his character. Though I got the idea from reading and writing fanfiction (I'll admit it - I like fanfiction!), it's still a logical explanation since I don't think we have any indication that Zeff had anything to do with his chivalry.
That's my suspicion about Dragon actually. But I really don't know enough about him to say why. Just a hunch I guess. Do you think any of the others will be villains, Dixxy?
Yeah, something about Dragon is a bit fishy. He doesn't exactly look like he wants to meet Luffy for cookies and milk - I wouldn't actually be surprised if Dragon was looking to somehow get Luffy involved in his revolution.
Well, Yassopp is with Shank's crew, but it's hard to say exactly what will happen there. It could be an alliance (at the very least Shanks seems to have some concern for Ace and that concern might extend to Luffy, especially when he realizes that Luffy's kept his promise to return the hat to him after TEN YEARS). There could be some issues between Yassopp and Usopp but I don't think it would be a villainous type thing.
Franky's dad we know little enough about that he could be anything.
We can assume Robin's mother dead (and he father is likely dead as well, including the "Robin is Roger's daughter" theory). With Zoro, Nami, and Sanji we don't really know enough about their birth parents to accurately predict whether they'd be villains or not - for all we know they're the One Piece equivalents of hippies. (Bellemere is dead and both Zeff and Genzo seem to be pro-Straw Hat for the moment - I don't recall Zoro's sensei's reaction to his bounty). Chopper's birth parents. . . are reindeer. Unless they ate DFs or something. . . probably not a threat.