Chrome Googles first browser is in beta and the other browser players don't want to share the playing field. I know that if I was Microsoft I sure wouldn't want Chrome entering the Browser wars with their new Internet Explorer 8 which crashes and will never work again if a tab crashes.
Yes Internet Explorer 8 is in Beta 2 and still has plenty of bugs. Chrome has one security bug that everyone is focusing on not thinking about how many security bugs their first browser had and how many bugs they still do have. I can't wait for Chrome to be out of beta.