I really hope the other Scooby figure is sitting, it's just a crime to have the Mystery Machine AND Shaggy's motorcycle with a side-car but no sitting Scoob to put in them.
I really don't see how they can expand on the series. Minifigs sell the bricks and they pretty much capture the core of Scooby Doo with the sets they have lined up. Only thing is they could add some more classic monsters. I doubt slightly different prints of the main characters would be a huge draw.
Dude. Bro. Dude.
Scooby-Doo has been running since 1969. It's coming up on its 50th anniversary (and considering the first report mentioned that they'll be doing DTV movies for the next couple years, will very likely still be with Lego when it hits.)
There are TONS of things they can do to expand the theme. Look at SpongeBob. Look at TMNT (which IMO was killed off too soon due to the stupid movie). Yes they could do things as simple as new prints, they have more than enough episodes and movies and specials to pull from (haunted space station with Scooby and Shaggy in space suits, tropical island hula God with vacation prints, zombie island with them in colonial garb, etc) but there are many other characters they can introduce too that aren't guest stars from other franchises.
Shaggy' dad
Scooby-Dum
Yabba-Doo
SCRAPPY-DOO
The 13 Ghosts
The Ghoul School girls
The Scream Queens
Heck looking at Wikipedia Scooby's family alone could last for years. It'd be super easy too since it looks like Scooby's head is a separate piece, they'd just have to make different heads for the rest of his family (and a normal head for Scrappy-Doo on a brown minifig body with kid legs) But there's also all the classic monsters (yes this wave has the Black Knight and Headless Horseman but what about the Deep Sea Diver? The Ghoul? The Yeti?), all the new monsters from the ugly ugly new show, locations like a funhouse or a barn or a theater, I could see them getting 3 waves out of the license easily. And it's out in August, what if it's just a yearly release around Halloween? I doubt it will be but I could see them each fall, new DTV Lego Scooby-Doo movie accompanied by a new wave of sets.
Basically I'm so impressed with what I've seen that I want as much of it as possible! I mean the Mystery Machine alone absolutely DESTROYS the one from that other company.