Over the past week or so, I have been seeing reports from Google users that the cursor is not showing up in the Google search box.
Google is aware of the issue and said it would be resolved soon, but it seems like even about a week later, some are still experiencing the issue.
The image above right shows a blinking cursor, which is typical of what you should see when you place your cursor in a text box. But for some users, there is no cursor showing up in the box even when you click in the box.
A Google Web Search Help thread:
When Google.com loads, the flashing cursor is inside the search box and you can start typing right away. With Google.ca you have to move the mouse into the search box, click, then start typing.
I believe the issue is only affecting some Internet Explorer users, including IE9 users.
Forum discussion at Google Web Search Help.