I get email on Spore news. I've been following the development of this game since it received such high acclaim at E3 - what - almost 3 years ago now? So I heard about this editor pretty quickly after they decided to go this route, and I've been trying to sort out what I think about it ever since then. I think I've come to a conclusion.
I'm for it. I don't think the 10$ is really purchasing game content. If it were solely that, then I would agree that they are charging twice for the same thing. What they're actually selling, however (my opinion), is time. Time for you to play with creatures before the game comes out. Even if those creatures could NOT be imported into the game at release (and my understanding is that they can be), becoming familiar with the editor and all of its possibilities is a product with a value. In this case, the value is 10 dollars, and it is up to the consumer whether or not they think this product is worth that. There's basic capitalism for ya

Myself, I'm on the fence as to whether or not I want that product for 10$. I have blown 10$ on sillier things, so I just might if it's downloadable. If I have to order it and wait for it to arrive, (no stores in Italy are likely to stock it), then probably not.