Maybe I'm being a stickler, but I'm having a hard time thinking any actress in Hollywood could pull off Jameson, even if they wanted. The woman has one chin plant (whatever) and sported two, yes TWO rounds of breast implants to make a big triple-D. Unless they're planning to show her life without all the sex (which would be dumb as that would drastically cut into the potential audience), they've got to have a woman with ... at least grapefruits, if not basketballs, resting in their bra.
IGN offers the following actresses: Fergie, Heather Graham, Erica Durance, Rachel McAdams and Jessica Simpson. Okay, I'm on board with Fergie. But the rest really aren't porn-star endowed, since I think they are all sporting their natural curves. Check it out for yourself (no nudity, but of course, there is cleavage): natural, implanted, natural, implanted, natural, implanted, natural and implanted. I wouldn't be surprised if Simpson got even bigger and took on the role. She might be refusing it now, but it isn't like she has many options. I think they're going to have a hard time casting this sucker, so don't be surprised if we're left wondering for a while.