I can't belive it myself but in my area competitors rank better without keywords meta tag. #1 directly doesn't have it so SE pick body text where they have good keyword density and description in SE result picks "key 1 bla, key 2bla" Others doing same rank better than my well organized and descriptive meta tag keyword and description.
We have got the same findings as silverbytes, but only for the keyword meta. Description is fine and utile, as long as it is different for every page, and what's even more important, SE tend to use the Description as snipped. Great place to put useful copy.