Because an application with a complicated set of external dependencies was ported warning-free to the newest version of Rails in a matter of hours, within days of the new version's release?
"Merb has an API. You might be wondering why having an API is awesome. Well, the truth is that the Merb Team spent time marking methods public, which are guaranteed to not break until the next major release (any change to the public API will be well documented). There is also a plugin API meaning that plugin developers won’t have to worry about upgrades if they stick to the plugin API."
It'll be interesting to see how well it works in the coming releases of Merb.
I'm not being a hater, just saying it hasn't been tested. Hopefully they can pull off upgrades more smoothly than Rails and Rails can learn from it. That way everyone wins.
