This is a darn interesting question, and one that clearly isn't cut and dry because there's a lot of debate in the SEO community on this topic.
The question is really: everything else being equal, would a ".com" be ranked more highly than a ".cn" or a ".fm" or similar?
My answer: yes.
Of course, since Google uses at least 180 different factors when it calculates Search Engine Results Placement (SERPs), the odds of having two pages with the exactly same score other than domain name seems exceptionally unlikely: if two pages were the same, then the newer file would suffer from a duplicate content penalty!
Nonetheless, I believe that there's also a psychological issue too, and know that I have a higher degree of confidence buying from a ".com" company than a ".cn" or ".cz" company, though I own ".com", ".net", ".org" and ".info" domains. No ".mil" yet. :-)
So if you have the choice between a splendid non-mainstream TLD domain name and a crummy, obscure name that's a ".com", I would suggest that you pick the former, not the latter. But then again, I believe that the vast majority of people come to a site because of the content, through search engines, so a human-readable domain might not be that important anyway.
I think you'd also find the following article worth reading:
• Does your domain name affect your search engine ranking?
Sign up for my weekly AskDaveTaylor Newsletter and you'll receive even more tech and gadget help
right to your inbox, along with exclusive news and industry updates. It's good stuff. I promise!
The way this is written it is almost as if your TLD is used as a tie-breaker. I am sure this is not the case, just the way you used your example to show the small significance of it in the big scheme of things.
So is it a sliding scale with .com on top and .(country code) at the bottom?
I do agree about the psychological issues. I dont think that applies to .net or .org as much as a .cz might make someone a little weary.