From the point of view of the user, I strongly subscribe to the school of thought that says build it working for everyone and enhance for the users that have better browsers. These buttons, as the post itself says at the end, are just not ready for production.
I missed the part that says it's not ready for production when I first read it. Here's part of the quote from the end:
> This is just a demo and not meant to be used on your next project that targets the average internet user.
Of course, when you're pushing the envelope, you're pretty much by definition going to leave the laggards who stick to older technology behind.