How to determine what new products and classifications have been added by WSUS

You can do this in an administrative PowerShell:

cls

[reflection.assembly]::LoadWithPartialName("Microsoft.UpdateServices.Administration") | out-null

if (!$wsus) {
             $wsus = [Microsoft.UpdateServices.Administration.AdminProxy]::GetUpdateServer() 
            }

$wsus.GetUpdateClassifications("$((Get-Date).AddDays(-31))","$(Get-Date)") | select Title, Description, Releasenotes, arrivaldate
$wsus.GetUpdateCategories("$((Get-Date).AddDays(-31))","$(Get-Date)") | select Title, Description, Releasenotes, arrivaldate

This will list all classifications and categories added in the past 31 days.

I find the easiest way is to keep an eye on the WSUS Product Team Blog here. The only other way I have found is to manually go through the list, but that can be painful at times.

The only way to I know of is to watch for message you have above. (I check WSUS once every a week as a matter of routine)

Then go to the update services mmc | options | Product and Classifications

Once I have that open I have used my favorite note taking app to write down what I have checked previous. Then I do a stare and compare to determine which ones have changed.

You can examine the "Synchronizations" tab, and see where the column "New updates" is non-zero. Right-click and choose "Sychronization report".