I for one don't understand why it needs both? Wouldn't it be a lot simpler to use only one or the other?
The whole article makes me yearn for the Python "there's just one way to do it" philosophy. It's one thing to have a special-case syntax for brevity or readability; it's another thing to have several equivalent all-purpose syntaxes. I get that Ruby 1.9 is transitional; hopefully the old syntaxes will be banished in Ruby 2.