A victory of this scale would stablize politics for a while, and Hatoyama will be premier for the next 4 years, I suspect. As for LDP, they will face an identity crisis once they lose the perception of "the Party", and may become increasingly ultra-nationalistic.

I would submit that this change should have happened in 2001 when LDP was no longer considered a party of valuable policy and experience. Koizumi prolonged its life a bit longer than necessary.

I will become a patissier, God willing.