It appears that the exploit in IE briefly mentioned a few days ago is causing a serious reaction: SteveAU writes "Microsoft has begun flooding media outlets with information advising users to switch to an alternate browser while a serious security flaw is being patched. The flaw, which affects all versions of Microsoft Internet Explorer, is manifested via malware and has infected over 6,000 sites thus far. Microsoft states: 'The vulnerability exists as an invalid pointer reference in the data-binding function of Internet Explorer. When data binding is enabled (which is the default state), it is possible under certain conditions for an object to be released without updating the array length, leaving the potential to access the deleted object's memory space. This can cause Internet Explorer to exit unexpectedly, in a state that is exploitable.'" According to the BBC report, though, Microsoft itself is only asking that users be "vigilant while it investigated and prepared an emergency patch"; it's outside experts who say to dump IE (at least for now).
Update: 12/16 21:11 GMT by KD : Microsoft will issue an emergency critical update for IE tomorrow.