We don't all forget that (one will come across similar remarks by other members just by checking this topic alone). And during such discussions I've even gone so far in the past few years as to say that the original DS fans are pretty much an insignificant group so far as the demographic WB will be mostly marketing the film to and hoping to attract.
That being said though, bringing new story elements can only help matters because, even discounting the original fans, there are still millions of people in the potential audience for the film who are aware of what the DS storyline has been in the past through exposure to the original series on the Sci-Fi Channel and the '91 series on NBC, the Sci-Fi Channel, and most recently Chiller. That segment of the audience needs to be attracted to the film, but no one wants to see them as bored to death with a complete rehash as many original fans would be.
Don't get me wrong - I've never meant to imply that everything that's come before should be thrown out in order to go in a completely new direction. I'm simply saying add enough new elements so that the storyline appears fresh and exciting to not only the people who know nothing about DS, but also to those who do...
And just to put things in a bit of perspective, wanting to see new elements brought to new versions of DS isn't exclusive to the forum or even new because fans were crying for it with the '04 WB pilot, the proposed '02 FOX pilot, the proposed DS musical, and even in the various fanzines that were around when the '91 series was in development and the '93 film scripts based on the '91 series were being shopped around.