They never went away, a pure css game is very obviously not going to work in ie6, there is nothing for it to degrade to, some people push the standards (mostly fun experiments) and some people have to be very careful about browser support (the amazons of the world)
Sure, for experiments like this that are playing with vendor specific properties. This is an outlier.
The great thing now is, for most regular old websites, I can just write the CSS and expect it to work reasonably well in any of the latest generation browsers.
But we're back to the days of "works best in so-and-so browser".
(no FF3/4 or IE9 or Opera11 support)