Until I saw your posting, I never heard of this tld. And it seems an odd choice - what's the significance of having "everybody" as a tld? And, of course, みんな has no meaning in Chinese, so it's kind of irrelevant whether some of the kanji are also readable in Chinese.
Maybe Google will promote this heavily in Japan. Even then, it's an uphill battle, as IDNs have not caught on in Japan - most Japanese are completely unaware of them. On top of that, there is no domain industry to speak of in Japan for any kind of name. "Resellers" may buy them, but end-users for the most part place no value on domain names at all.
So, if the Japanese become interested in domains, and if they start using IDNs in a big way, and if this みんな tld becomes a hit, you've got some good keywords. But I think that's too many hurdles. (Not to mention the Japanese economy is headed off a cliff.)
Sorry to be negative - maybe I'm short-sighted. I wouldn't pay the renewal fees for these, personally. But you might find a domain investor who's interested.