I dont have proof but I think google doesnt ignoer the meta keywords. I had a site that was just sitting there with nothing on it except for a meta tag i was working on for a different site (i didnt wanna save it to a note file on my work computer so i saved it to that site that wasnt doing anything) After about 4 months I noticed some traffic to it. (never submitted it anywhere...total blank site except meta) I was getting traffic meant for a porn site and this sites URL had nothing to do with porn. So somehow it was indexed by google....
I had my site without any meta before, and it ranked pretty well... I added both now and the idea behind is this: descriptions are good for humans, since they see what page is about etc. Keywords help with yahoo - so don't ignore them, they are still important