While trivial, it's not good marketing.
The only instance I see country TLDs as being actually useful is for localized versions of said sites ... Google already does it, but it's not like it is useful for an email address to end with "gmail.ru", quite the contrary.
A better suggestion would be to use custom TLDs based on some category your website fits into ... like ".fm" for radio, or ".info" for hosting your personal resume, or ".doc" for archives of documents, and so on.
Sure, people are very accustomed to .com domains, but who's to blame for that?
Also a brand is a brand ... say you have the luck of registering "google.nu" ... most likely Google can take it from you by force ;)
your plan would pretty much eliminate 99% of websites.
Ebay would tell ICANN redirct ebay.com to ebay.co.us indefinitely. And maybe at some point in the future .com is entirely eliminated.