The Google Analytics Team announced on their Analytics blog that they will stop supporting the old browser Internet Explorer 8 (IE8) by the end of 2013.
This doesn’t mean that visits from people accessing your website using IE8 won’t be in the reports, but it does mean that you won’t be able to use Google Analytics to check your website statistics if you are trying to do this via IE8.
To focus on supporting modern browsers, we are deprecating official compatibility of Google Analytics with Microsoft Internet Explorer 8 (IE8) at the end of 2013. We decided to do this to both accelerate the pace at which we can innovate new product features, and to facilitate adoption of newer web technologies in the design of the Google Analytics product. Our ultimate goal is to provide a superior user experience for every GA user. As a note, we’ll of course continue to measure traffic from IE8 browsers to your website.
So if you’re still running IE8 now would be a good time to start thinking about upgrading.