lol.
From all we know so far, blu-ray takes much longer to load up (disc-wise).
While a 16x dvd drive (which xbox 2 will most likely be using) runs at 133x (correct me if im wrong, im just ballparking. someone else posted these blu-ray vs dvd specs, im just recalling the info) while a blu-ray runs at around 20-ish.
That doesn't have much to do about loading times, but it's a shot.
Also, the cell chip has a much less clock speed compared to what the Xbox2 will be using (g5), so that will most likely play a part.
Why do you ask about the 'loading times', of all things. And, omgosh, a new thread for it? It's ok, if anyone finds any updates on these fashionable 'loading times', I'm sure they can find where to post it.