I beleive titles and description are important. when you are in google webmaster tools, if you have some duplicate meta tags between pages, it will report it as a problem.
If you are missing meta tags, your website will not rank in ANY search engine. Period. JK. Take a look around, there are many pages at the top without any real work put into their meta tags. Many CMS software programs have the meta tags stuffed with the CMS name in the meta tags (Joomla, etc.), and users are ranking at the top in their areas with the default meta tags still in there. The question is, did google EVER use the meta tags? That was the first "black hat" way probably...
tyler_durden, You wrote "If you are missing meta tags, your website will not rank in ANY search engine. Period." You are sure?
david001, You wrote: "Meta Tags important resources by which a search engine crawler knows what the page is about..." True about three years ago but the SEs are getting smarter.
if u will not use meta tags how spider bot will determine ur important keywords. They are still important.
But I think it is still important. If you check Google webmaster tools you can see still Google value them so much.
yes, tags are NOT that important anymore. That being said, i am certain AdSense bot still reads them to determine what a site is about.
Fygi, You wrote "you often enter long queries in search engines?" Many times if I want to look for info related to long tail keywords like "video game guides walkthroughs" to build site/blog for niche market where the competition is low but there is money to be made. See http://www.google.com/search?hl=en&q=video+game+guides+walkthroughs&btnG=Search At the time of writing http://videogameguideswalkthroughs.blogspot.com/ is still available. If you don't know what I'm talking about and the value of the blog above, google "Niche Blog Affiliate Profits System" (with "").