I think it’s ok. It can’t have too much weight, otherwise Google will lose people searching, when they always get same results. On the other hand – what about news etc.? If I search for example daily news or some special topics (i.e. swine flu) and if websites I read before did not update their news. What’s then? No. I think it is only one little piece.
I believe, keeping a website up-to-date, having unique content is more important. And the bounce rate and how long people will stay.