Just want to note, as the author, that this post is almost 18 months old now and I don't necessarily stand by them all anymore ;-) (I'd need to go back and re-edit to make that assertion..)
It may be helpful to move the datestamps of Ruby Inside's entries up to the top, and more prominently style them (size, colour). I was this close to chastising you for not having datestamps at all :) until I noticed the one for this article in small, non-descript black text between the post and the comments.
This is one of those things where results outweigh logic and decency. This post would almost certainly not have seen renewed interest in the last few weeks if the date/time were easily noticeable. It's quite a common "trick" on blogs now. Some people just immediately leave if they're on a post that's over a year old.
I'm sceptical of that reasoning. A post can have enough merit to outweight the negative impression old age gives. I think the lack of a datestamp can often lead to confusion or mild bewilderment as the reader tries to guesstimate time context. "Current developments for project foobar include A, B, and C. On the roadmap are D, E and F." How current is that "current"?
I certainly won't leave such posts just because they are over a year old! The post was interesting for it's contents and the dates imho should have no effect.