Have you followed all the steps for Google Authorship on your blog but your profile photo still does not appear in the search result snippet? It could be the image itself that is to blame.
After waiting almost a year and still not seeing my profile pic appear in Google search results, despite it apparently working fine in the Google Structured Data Testing Tool, I read on this post that it could be the fault of the photo itself.
Apparently, your photo can be suppressed if you are wearing sunglasses or if the image is filtered too much, amongst other things. Obviously I was guilty on two counts. Two days after updating my photo to one without filtering or sunglasses, it started appearing in search results.