I really don't know about LBP, particularly as far as it being a 'killer app'. I'm sure Sony would love for it to be big, and I hope they do push it as far as advertising and everything to get it into people's faces. I know I certainly want it, but for people who are not like me/us and who don't know much about it may just write it off as some childish game for babies.

In fact, it is rather similar to Boom Blox in this regard.

I think it could become one of the PS3's 'essential games', but I don't know if it could be classified as a 'killer app' until after we know of its success. I think part of being a killer app is actually selling a lot of that particular product.