Except in rare cases (like Wei Dai's Fair Division of Black-Hole Negentropy) I'm still using article upvotes to partially determine whether to promote articles to the front page - some informal mixture of "number of upvotes" + "editor's judgment". I mention this because while comment voting is still healthy, the amount of article voting seems to be dropping off. As of now I'm still drawing the inference that no one thinks "Are You Anosognosic?" worthy of promotion, or wants to see similar articles from me in the future - since other articles have at least gotten more votes than 0. But as the amount of article voting diminishes, it becomes harder to trust such inferences. Maybe people liked that article (or others I haven't promoted) and just didn't bother to upvote.
I'm posting this observation just in case people figure that upvoting articles doesn't make a difference. It does. It also encourages authors to write similar posts in the future, or alternatively not.
You could make voting a post mandatory to comment on that post, so to submit a comment you get prompted to vote it up or down (or maybe neutral)
Or maybe just by having the vote up/down/neutral buttons next to the comment submit button, right in peoples faces, would make them more likely to vote.