A couple of weeks ago I did a post looking at 1.9.3 and 1.9.4 and the differences involved (including a video presentation by Yugui): http://www.rubyinside.com/ruby-1-9-3-introduction-and-change...

Now, plug alert..

I'm having a 2 day 50% off on Ruby 1.9 Walkthrough to celebrate: http://www.rubyinside.com/19walkthrough/ .. Yes, totally a plug, but there isn't any more up to date walkthrough of 1.9 (which includes 1.9.3) so I'll take my chances ;-)