I've seen book providing a "chapters at a glance" part, just before the real table of content.
Such an inverted pyramid is exactly the consequence Nielson draw from the "F shape pattern" (http://www.useit.com/alertbox/reading_pattern.html). And that's my critque: i don't see the most important things there are to be sayed about Haskell in the top left corner.
For the hompage we're talking about, glancing is even simpler since everything is on the same page and you can scroll it quite easily.
I don't agree that "everything on one page" makes comprehension easier.
I'm not sure hiding a level of the hierarchy of information behind a few clicks make things easier.
That depends on which task we are talking about: - getting an overview of all available information, or - finding exactly what you are looking for I think we should optimize for the latter, where "What is Haskell?" being the most improtant question.