The only good thing about not using .com is that the US government doesn't control it (or so I've heard).
The downside, of course, is that someone else controls it - .ly comes to mind.
.is is good though.
Except both of those tlds are a lot more expensive than a .com and as the article notes, do NOT register with the general public. So if you have the money to spend on a vanity domain that you don't need to have "regular" people remember, it is an option.
Being a serial ideas man, I'm always coming up with different things and am always purchasing domain names that I don't really use more than once merely for experiments in hopes of them being the next big thing. The cost of registering these new popular domain names is sometimes astronomical compare the cost of an .io, .fm or .tv domain to the cost of a .com or .net. Just come up with an even more unique .com if you want to register a domain.
Does the world really need a TLD "for geeks"?
This feels like a money grab to me, and £60 ($93 US) to register a domain is a pretty steep premium.
Of course it's a money grab. So are .ly domains, which are over $100 USD. That doesn't stop every other startup from buying them however.
.io does have some good names available, though it's pricey. billy dot io was my little splurge (but is just an alias to my full name dot com)