Heroku might have expanded its embrace to include Node.js and Clojure, but its heart is still with Ruby. To wit, Ruby creator Yukihiro Matsumoto is joining the company as its chief architect for Ruby. This type of hire is nothing new in the cloud computing world, where strong developer traction is critical to a company’s success. Node.js proponent Joyent now employs its creator, Ryan Dahl, and sev