Well, not quite, there are some nice new features.
First of all, I wanted to learn Backbone.js and work it in to the mineConics code. I started small but it wasn't long before I realized that I should just recode the entire app in Backbone. The new code base is about 1/3 smaller than the old jQuery-based app. I still use jQuery in the app, it works really well with Backbone. One of the things that I'm excited about is that Backbone will allow me to implement new features much more quickly.
As for things not looking completely the same, I worked some new features in to the site. I reduced the scale of the cartesian plane so that the default view is "larger". Some users had stated that their first impression of the page was "this is too small to draw the shape I want", so hopefully the new look will give them more confidence in the app.
I added a mouse coordinate tracker to help users find their locations. This is something that I should have had from the beginning, very easy to implement.
Also, I added Local Storage support. It will save whatever design you were working on and reload it when you come back to the site. Soon I'll roll out the ability to save multiple designs, then I'll add a feature allowing you to share designs. Oh, and 'save' doesn't currently do anything, I just didn't want 'clear' to be lonely.
As always, please tell me if you notice any bugs, have a feature you'd like to request, or have any comments in general!