Here is the browser market share for April 2014, based on traffic to my top site (number in parentheses shows change from March 2014):
Google Chrome: 48.25% (+0.78%)
IE: 23.74% (+0.17%)
Firefox: 21.25% (-0.41%)
Safari: 3.34% (-0.11%)
Opera: 0.89% (-0.12%)
In April, Google Chrome was again the winner, and now is approaching the 50% mark. The big news during the month, though, was the zero-day vulnerability discovered on IE. This was complicated by the fact that this happened after Microsoft stopped its support for Windows XP, meaning that Microsoft will not issue an update to fix this problem for Windows XP users. As a result, those who are still using XP are exposed to this attack. Even though there are workarounds for XP users, the steps are relatively complicated, so it is quite possible that very few Windows XP users actually did that.
This problem is significant enough that US CERT (US Computer Emergency Readiness Team) even issued a warning to XP users to “consider using an alternate browser“. Indeed, the easiest thing for XP users to do is to stopping using IE. Even though the April numbers did not reflect this (most likely because the discovery came late during the month), I expect IE usage to take a dip of at least 0.5% in May.