An article worth reading: Of snakes and rubies; Or why I chose Python over Ruby
Actually makes me want to learn Python. Although I wouldn't let go of Ruby so quickly.
Something interesting that I found: http://raa.ruby-lang.org/project/ruby-python
A Ruby library that allows Python use within Ruby code. Looks interesting. But I wonder why not much work has been done to take it forward. Seems outdated (last updated in 2000).