Some more info: The script is being written by Siavash Farahani. He doesn't seem to have any major credits that I can see -- IMDB lists him as only having directed one movie (Ingenue, in 1999).
In addition, IGN has this to say about Raimi directing:
[The Hollywood Reporter] claims Raimi is not attached to direct at this time but IGN has been informed otherwise by sources. THR also did not have any further comment on IGN's report that the film might also include appearances by other Street & Smith heroes so that remains only a rumor at this time.
It's worth noting that it was IGN that first broke the news about this project almost a week ago, so there may be some truth to their report that Raimi will direct.