Something I haven't seen discussed: how are web browsers going to handle somebody typing a generic keyword that is also TLD into the address bar? The chrome-style omnibar that every browser has since adopted is predicated on the fact that URLs are fairly easily recognizable.
But if amazon owns "books" and hosts something at http://books/, should browsers navigate to Amazon whenever someone attempts to search for "books"?
[Actually, is it even allowed to host A records directly on a TLD? I've been reading through RFCs and haven't seen it explicitly disallowed, but nobody seems to have done it with a currently-available TLD.]
Yes. Tonga turned their TLD `.to` into a domain shortener, although because of the browser issue you mention it generally had to be accessed via http://to./
However, it hasn't been available for a long time now.
EDIT: As pointed out below, http://ac/ points to a real website
Browser can and sometimes do override DNS. The omnibar is one recent example. This is obviously very bad.
It is like the NXDOMAIN problem.
Is it the web? Or is it some company's interpretation of the web? "In this situation, when the user types ______ the user should be directed to ______."
But if amazon owns "books" and hosts something at http://books/, should browsers navigate to Amazon whenever someone attempts to search for "books"?
[Actually, is it even allowed to host A records directly on a TLD? I've been reading through RFCs and haven't seen it explicitly disallowed, but nobody seems to have done it with a currently-available TLD.]