In addition, the "thousands of episodes" which were originally announced only include these few in the Scooby department:
Scooby-Doo, Where Are You episodes 1-13
What's New Scooby-Doo episodes 1-13
Be Cool Scooby-Doo episodes 1-13
Scooby-Doo in: Arabian Nights
Scooby-Doo Meets the Boo Brothers
Scooby-Doo and the Reluctant Werewolf
Scooby-Doo and the Witch's Ghost
Scooby-Doo and the Alien Invaders
Scooby-Doo and the Monster of Mexico
Scooby-Doo 4: Curse of the Lake Monster
However, there is some hope for new episodes still, as Boomerang's FAQ lists that new content will be posted weekly.
Generally I try to keep my personal synthesis out of news posts, but I must say that I really hope new episodes are added quickly, because right now their "amazing service" (the term they used to promote it in one of their email promos) gets a big thumbs down in my book.
I'll keep you all updated if there's any movement with new episodes, but for now you can try a free trial of the service for a limited time at Boomerang.com.