A couple years ago This question was easy to answer. Internet explorer pretty much dominated the browser industry. However things are changing, and in my opinion its for the better. I just checked my browser stats to see who is using what, when they visit my website. Below are the results.
Firefox 43.8% 219 Hits
Internet Explorer 26.2% 131 Hits
Chrome 11.6% 58 Hits
Mobile Devices 8.4% 42 Hits
Safari 4.4% 22 Hits
Opera 1.8% 9 Hits
These stats show that Firefox is leading Internet Explorer for visits on my website. As a web developer, I see this as an excellent change. One of the tedious jobs that comes with web development is cross browser compatibility. And the one browser that is always the first to display websites incorrectly, is always Internet Explorer.
I hope that this is an indication that IE is going away. I know it wont be immediate, and probably wont happen for years and years, but I can hope.