If you look at long term sales ranking, BD is much more stable & consistent regarding buying of movies. To me, this kinda indicates that a lot of BD supporters are more casual buyers. On the hd dvd side, you have huge peaks & dropoffs. When HD gets new releases or buy days, everyone piles in, and can momentarily overtake BD's rankings, but then the #s quickly drops off. IMO Transformers should follow this pattern.
I think hd can pull ahead with the pre-orders, but BD eventually catches up & overtakes as more of the "casual enthusist" that represents ps3 owners jump in. Bd has a lower overall attach rate, but the upside of that is that they have more "untapped potential". As the poster above me mentioned, once you have a sale or hit movie released, BD comes back swinging.
Sony pay me 10 beeeelion dollars to plant blu-ray seeeeds.