Matt Cutts has released a new Webmaster video determining the importance of Metatags & how they should be created.
Here’s the question Cutts is answering to in the video:
Is it necessary for each single page within my website to have a unique metatag description?
Cutts suggested that you can either have a unique metatag description or you can choose to have no metatag description. However, you should not have a duplicate metatag description. He also added that when you register and verify your website on free Google Webmaster Tools, the team will tell you if it sees duplicate metatag description or something worth avoiding.
Matt added that it is usually not possible for you to come up with a unique metatag for every page on your website. There are however, a few pages like the homepage or those with important ROI that should have unique & handcrafted meta descriptions. But, in general, rather than have one meta tag description repeated over and over on your website, Cutts said he would either go ahead and make sure that there's a unique one for pages that really matter or just leave it off and Google will generate the snippet for you. But, do not have the duplicate ones on the page.
Here's the video:Matt Cutts on Unique Metatags & If They are Necessary for Each Page!,