I was researching this last night too for a new site. I have mixed feelings about this too. I think at one point in time it was used by humans more often but nowadays not as much. However, if you are going to spend $299 to be listed, it somehow says to the SE
out there that you are actually a legit business and not just a hobby site and want to be taken seriously. Right now I am looking more at my particular market to see if there are any directories out there who can pass me some link juice without paying that hefty price, while providing me some keyword links as well. The grey bars in Yahoo directory pages that would link to me does not give me enough reasons to enlist with them.