/me checks again after reading this thread.
WOW. That's horrific. Not only does it give ZERO indication that there is actually content there besides a background image/title.
The scrolling is not only bad per-click the z-axis mouse buttons, as cnp said. This same nonsense makes Page{Up,Down} only "scroll" (advance the animation) like an inch. In fact, the only way this even seems to approach "usable" is if you hold down the key for autorepeat, which gives it a constant "frame-rate".
This type of intro is yet another example of a style of design that really wishes the web/HTML wasn't a "document" with hierarchal markup, and try to force movie/tv style over how it is seen.
As others have said - should have just been if a flash intro/video instead.
From the end: "Really, anything is possible …"
Ok, I made the zombocom reference in a reply below before seeing that - now I almost wonder if this is some sort of waaaaaay-too-subtle parody or something?
[1] Extra broken, because the site detects browser width and overlays the ENTIRE PAGE with a black screen that says:
"Whoops! Right now this demo doesn't handle resizing or browsers less than 1000px wide. Reload this page or get on a laptop!"
So because a potential source of layout problems, such as my browser in a portrait-mode-like aspect ratio and too narrow for the background image, it's better to slam the door so the user sees nothing? How nice. If I'd seen the "broken" version, I might have had to drag my window a bit bigger. Or how about "background: center 100% no-repeat fixed url(...);"?