It’s official! I don’t think any professional in the SEO world has taken notice of the keyword Meta tag in years but just to make it clear Google have decided to create an official post to advise they do not use the keyword Meta tag in Natural Search.
Of course a few lesser engine may take notice, so why not save a line of code and simply miss them out!
Official Posts can be read here:
- http://googlewebmastercentral.blogspot.com/2009/09/google-does-not-use-keywords-meta-tag.html
- http://www.mattcutts.com/blog/keywords-meta-tag-in-web-search/
Neil Walker is the founder of SEO at Just Search Ltd who rank on the 1st page of Google UK for "SEO". He has over 7 years experience and dealt with over 2500 clients SEO over the years. He has only started to proactively blog in the past 4 months by running "SEO Mad" - He hopes you find it interesting. 
Just a quick note to say the Google Webmaster post also included:
“Even though we sometimes use the description meta tag for the snippets we show, we still don’t use the description meta tag in our ranking.”
This shows that you shouldn’t SPAM your Meta Description and use it for conversion and click through.
I dont see any harm in including the meta tags if it makes you feel comfortable, as long as you dont spam it up with to much info. If its not broken, dont try and fix it.