If you’re still running IE6 it’s definitely time to upgrade. Last week some exploits targeting Internet Explorer 6 were made public and we also released a Security Advisor describing this; Microsoft Security Advisor 979352. Later versions of IE are not effected because of the improved security features. Here is an official statement from us:
Microsoft is aware of public exploit code released that impacts customers using Internet Explorer 6. Customers using Internet Explorer 8 are not affected by currently known attacks and exploits due to the improved security protections in IE8. We recommend that all customers immediately upgrade to Internet Explorer 8. Customers should also consider applying the workarounds and mitigations provided in the Security Advisory.
Internet Explorer 8 is available at http://www.microsoft.com/ie
Microsoft teams are continuing to work around the clock on an update and we will take appropriate action to protect customers when the update has met the quality bar for broad distribution. That may include releasing the update out-of-band.
More information including the Microsoft Security Advisory 979352 and enhanced security features available in Internet Explorer 8 are available at: Microsoft Security Response Center (MSRC) blog.
You also find some information comparing how this affects browsers and platform in this blog post.