Now that Stack Overflow is over a year old, it's going to be increasingly likely that you will run into questions and answers which are also many months old. It seems like the way that a date is formatted is like this:
IF date is older than one year format = day month year time // eg: 10 Aug 08 at 12:15 ELSE format = day month time // eg: 15 Aug at 14:35
Maybe it's just me, but this makes it slightly confusing about how old that last example is. I have to think to myself that "today is the 14th, therefore
'15 Aug' means
I know it's not really a massive problem, and it probably is an edge case (though this "edge" will be getting thicker over the next few months), but you could avoid the situation altogether by changing the date-formatting cutoff point to be 6 or 9 months. Given today is 14th August 2009, anyone can easily and quickly tell that
15 Dec means 2008.
And yes I do realise that the full ISO date is stored as a tooltip on each date