I know that this may seem like a strange idea but:
  Just because something is a great way for someone to make money does not
  mean that it is a good idea.

The reason that people type a product name into the url box is two fold.  One
as kre said browser writers made this go somewhere that may be useful.  The
other reason is that all search engines, directories (etc) are all hopeless.
Say you want to find a company that sells widgets.  Try to find a site on the
Internet that will give you a page with just a simple list urls pointing to
companies that will sell you widgets.  IMHO all the search engines, portals
etc are stuffed because they either try to solve too many problems, or have
been too commercially driven, with greedy men trying to control to many
things.

Some people may think they are loosing business to amazon etc because they
can't register books.com.au.  I will state I know next to nothing about
marketing etc, but I really doubt this is this is the case.  Perhaps there is
something to be gained in the short term, but beyond that?

The real estate/prime location argument is bogus.  I buy from the local
shopping centre because physically it is easier than going to the other side
of the city.  If my choice is between typing fredsbooks.com.au and
yankeestore.com, I am not going to base my decision based on which one has
less characters.  If I am parting with my money more I usually spend at least
a few minutes looking around for good prices etc.

Here is a suggestion:
If we must have generic domain names, state that they must be run in some kind
of "open directory" structure (similar to what was suggested by another
poster).  Give rules like:
	.  One page is delivered for eg http://books.com.au/
        .  Anyone who wants to can ask that a link to their site is included
           on that page, as long as they actually sell that product etc.
        .  links are limited to two lines of text or a banner ad of size no
           greater than ...
        .  each entry is delivered in either alphabetic order or random order
           (we decide one or the other before starting this up)
        .  Any one can ask for a generic name as long they run it according
           to these rules
        .  All this is administered by a not for profit organisation, bound up
           in tight contracts etc.

For the record, I say that generic names should not be allowed but we allow
something like shop.au which is run this way.

-- 
Malcolm Caldwell - Network Supervisor             Email:malcolm§it.ntu.edu.au
Information Technology Support                    Ph:  +61 8 89466631
Northern Territory University,Darwin              Fax: +61 8 89466630
CASUARINA 0909 Australia