xhadow, you can use both, or either.
Regarding meta description being dead, yes this is widely accepted. However, savvy SEO's are still using it , selectively, and correctly. Why? well, the simplest method of stopping people abusing something is to tell everyone that that certain thing is no longer being monitored or read.
Does it do any harm to use meta keywords? no. Does it do any good? well, if used correctly, possibly, maybe, who knows. Ergo, there is no reason NOT to use them.