Three quotes, hopefully not out of useful context, that seem incongruous:

"Rubinius is about the join JRuby and MacRuby in the realm of GIL-less Ruby implementations"

"I spend my free time working on an alternative Ruby implementation which doesn’t use a GIL (MacRuby)"

"I respect Matz’ decision to keep the GIL even though, I would personally prefer to push the data safety responsibility to the developers. However, I do know that many Ruby developers would end up shooting themselves in the foot"

So developers using GIL-less MacRuby, JRuby and Rubinius are prone to foot shooting? I wish they'd blog about this more, I've never once heard a MacRuby or JRuby developer blog saying "I went back to MRI because I needed my Ruby code to be run more safely".