Statcounter:

Microsoft’s Internet Explorer (IE) browser has fallen below 50% of the worldwide market for the first time according to StatCounter. The company’s research arm, StatCounter Global Stats finds that Microsoft IE fell to 49.87% in September followed by Firefox with 31.5%. Google’s Chrome continues to increase market share at an impressive rate and has more than tripled from 3.69% in September 2009 to 11.54% in September this year.

That will keep dropping I would suspect – though I am hearing IE 9 is pretty nice.