Search EN Updates

Can we get a link to search the old EN Updates?  I'm not sure when they disapear/expire from the Dashboard- but sometimes I want to go back and look at an older "update".  For example, I remember seeing something there about a ppt file Coach P created to help folks navigate through the EN 4.0 Forum features and made a mental note to check it out when I got back from vacation.  But it's not in the "EN Update" section anymore and I can't seem to find where it might have been stored.