I think most people prefer the posts showing how long ago they were, instead of a date (which made everyone have to work it out all the time)
Although I agree that really old posts would be better to have a date, but it's so useful for new posts and it's either one or the other.
With blog posts though, I agree that it would be nice to have the actual date it was posted when you're reading the blog item - so that when you look back months later you can see the history.
I'll look into changing the date display on blog posts in the next few days.
(Oh, and thanks for your feedback! I always read feedback, and visit the forums every day although don't always post

)