Good news for Growl users running Mountain Lion. The notification system has been updated to version 2.0 with support for OS X's built-in Notification Center.
Now you can choose to have messages pop up in Growl or get pushed to Notification Center, keeping everything in one place. Also, Growl has support for more apps than Mountain Lion does, as it has been around for much longer. It's like getting Notification Center support for a whole lot of apps all at once.
This update also supports Prowl and Boxcar, further enhancing your mobile notification options. This is a free update for current Growl owners. Newcomers will pay US$4.