Well, the wife, who is most certainly anything but hardcore about gaming (she sort of likes the odd Mario game, but despises most other games I've owned) was talking about this "Little Planet" game the other day. I guess she heard about it somewhere. Now, not saying that this is a sign of market reception, but it pretty clearly has some mainstream appeal. It remains to be seen whether they can actually harness that with good marketing, but it's there.
For the record, I don't think it will be an instant hit.