Not a sequel or a remake, but a totally fresh start, apparently. Sources indicate that the mega-wealthy artist and author wants to "make a spooky, suspenseful thriller that will scare the crap out of you."
Apparently Mr. McFarlane is still at work on the screenplay, but promises the new "Spawn" movie will be quite a bit darker than the earlier one. I don’t care how dark it is, just make the thing less … stupid.
Source: Moviehole, Home Media Magazine