Yesterday on the Google Webmaster Blog, Maile posted and FAQ on using Google authorship, rel=author, on your site.
The one that I am glad was brought up was not to use authorship on product pages. I see it all too often and it just doesn't make sense. Authorship should be used for stories and content that is specifically tied to an author as something he is adding his own opinion to or something very unique. Product pages are not that.
You should use the reviews rich snippet. But that doesn't mean that product results should not have authorship. If you are doing a detailed review of a product, go ahead.
Here are some of the questions answered by the FAQs on the blog.
1. What kind of pages can be used with authorship? Short answer: Author based content.
2. Can I use a company mascot as an author and have authorship annotation in search results? For my pest control business, I’d like to write as the “Pied Piper.” Short answer: No.
3. If I use authorship on articles available in different languages, such as example.com/en/article1.html for English and example.com/fr/article1.html for the French translation, should I link to two separate author/Google+ profiles written in each language? Short answer: No.
4. Is it possible to add two authors for one article? Short answer: No.
5. How can I prevent Google from showing authorship? Short answer: Block Google.
6. What’s the difference between rel=author vs rel=publisher? Short answer: publisher is company related, author is person related.
7. Can I use authorship on my site’s property listings or product pages since one of my employees has customized the description? Short answer: No.
Forum discussion at Google+.