The whole point of a name space is to make things easier to remember.
This is the old invariant. It's varied. I'm still waiting for a proposal for a hierarchy which will hold 25,000,000 names and still have them all easy to remember, or easy to guess from external knowledge. The new "whole point of" the DNS name space is to provide names which change less often than IP addresses change. If we could do just that we'd be winning.
Maybe .com can be split by country that you are incorporated in and in the US moved under .us and further split by state of incorporation (or state in which you do primary business for unincorporated businesses and masquerades).
An excellent idea, in my opinion.
Perhaps in the US we could also do symbol.stock-exchg.com.us with a requirement that you be listed on that stock exchange (and maybe even delagated to the exchange), covering publicly held companies and do privately held companies by state if neccesary.
Almost anything that puts depth in the tree is "good". However, we should work toward a handful of different top level strategies -- and that hand is almost full already so we can't add indefinitely.