It was recent. Last week or so? I got a bar up at the top when I went to Blogger that said something along the lines of...your browser is no longer supported by Blogger so some aspects may no longer work properly.
They were not kidding. I could see blogs just fine, but when it came to actually creating a blog post, nothing was displaying properly in IE9.
Maybe this is something new and they haven't completely rolled out the changes yet? That is the only reason I can think of why some would be seeing the change and not all.
Chrome might be stable but it is also a very nosey browser. I only know this because my hubby is a techie and is adamant about not using Chrome. Google apparently uses it to do a lot of information collecting.