This is interesting because to date, Hollywood has seemed unsure about how to handle all these new media formats and how they're going to fit into the existing system. This hasn't been helped by the fact that some of the new formats have unclear financial benefits for studios. Possibly as a result, they haven't yet led to a flood of good quality content (I'm thinking primarily of online film and TV, which up to now has been the poor cousin, content-wise, of mainstream film). A TV series might have a secondary online show, but as shows like Harpers Island and it's online spin-off Harpers Globe demonstrated, the real money is being pumped into the TV version.
Leaving online content aside, there is also the supporting marketing that shows and films can do through other formats, such as mobile phone clips, DVD extras, online advertising, stuff like that. Some of that content uses additional footage, even additional characters and it's fitting that there is now a credit for producers that covers all these "other" formats.
But where does this leave the writer? What if you not only write the script, but also the comic book that supports or even inspires the film? What if you write the dialogue for the online advertising or write a short animated script for the DVDs extras? What if it's your online comedy show that leads to a script which you've written getting to the big screen?
I guess my question is: should the WGA be thinking of introducing a Transmedia Writer credit over the next few years?