Much of Merb's momentum has been merged into Rails 3, but one-time Engine Yard developer Daniel Neighman has found himself moving in a new direction, inspired by what they had once achieved with Merb Slices. Since then, he's taken fully-mountable Rack applications to the extreme in
Have you ever yearned for something like Rails's 
Can you remember what a hideous chore it was to deploy Ruby-based apps (Rails apps being a key example) before early 2008?
Testing is a firmly ingrained part of the Ruby culture: you probably ran across 

Most Ruby developers should be familiar with