The following discussion is on last week's "LOST", so - spoilers ahoy, if you haven't watched it yet. BTW... includes a side discussion on Billy, and what if he'd been on "LOST".
So I'm re-watching last week's episode and I get to the point where Desmond, heartbroken and helpless, tells Penny "I'm sorry... we're... not supposed to be together" - and suddenly, I see Billy! No, no, no - he's not on the screen, or in the background - it's Desmond's mouth, and there's something about the way he says the line - sort of drawing his mouth in a pinched line at the end - that reminds me of Billy. And, all over again, I think to myself "I really, really wonder if they wrote this part for Billy, but he couldn't take the part, so it went to Henry Ian Cusick." I mean - take the scene at the end... my god, could you imagine if it had been BILLY telling Charlie that he'd tried and tried to save him, but that fate tends to "course-correct"? *dies* How devastating that would be! And, of course, doing the scene with Penny; obviously, I can perfectly imagine it. Am I the only one thinking they meant this for Billy, at one time? (suggested by domie, of course!)
And, on a completely different note, I don't buy that silly scene in the bar at the end. I mean, yes, they set it up for Desmond to get all excited about the fact the he IS sane and he really did time-travel - but, hey, why does that make him think he can get back together with Penny? I assumed he decided not to marry Penny because he realized that there IS some kind of plan for him that he can't fight - so this should only confirm it, right? On the other hand, are they saying that the reason he broke up with Penny was because he thought he was losing his mind? I didn't get that idea at all.