What was the suggestion? It was to have a way to tell how many new items are in a folder versus how many you have marked as "keep new". Before if you marked any as keep new they simply reflected in the new number, so you might end up going back into the folder thinking there was something truly new, when all it was is stuff you wanted to keep for later. Now if you have marked any keep new in a folder it will display how many are new followed by a colon and then how many you have marked as keep new.
If you have not marked any keep new it will simply display the number of new without a colon. If there are no new ones then it doesn't display anything.
Missouri Governor's Office News (27)
If all are new and none are marked as keep new then it does not bother to put anything else.
IBM Redbooks | Lotus (0:1)
If the inverse of the one above is true, as in this case, then it displays a zero for new followed by the number of items marked as keep new.
The Car Blog (3:1)
If you have some of both then it will display the counts of both.
If there is neither, then it doesn't have any numbers displayed after it.
Thanks Bloglines! Maybe small compared to many out there, but with 246 feeds, I find this to be a handy feature.