Brightest Comet In 300+ Years, Q4 2013?

If the ISON comet (link here) survives its elliptical orbit close to the sun this year, it should be visible from October 2013 to January 2014.  One can track the progress of ISON at earthsky (link here).

It is interesting to me in this age of models and projection, that we can't get something as huge as a comet's elliptical orbit predicted with absolute precision, when Kepler and other scientists 400 years ago used to do it with hand calculations fairly predictably.  Yes, there's all sorts of variables to consider, that's true, but it strengthens my paradigm that complex models (financial, climate change, ocean rise, political election predictions) are often subject to unexpected forces that will skew the models.  Kudos to NASA for not stating the ISON will Absolutely be Brilliant in 2013 Q4... especially if it burns up as it gets to within a million miles of the sun.

So many moving parts...