Any way to send messages to Mavericks Notification Center from another machine on the local network?
You could ssh to the destination machine and run the following for each notification.

osascript -e 'display notification "Lorem ipsum dolor sit amet" with title "Title"'


Alternatively, there are a number of ways of running AppleScript remotely. You can do it with Keyboard Maestro, which allows you to run macros (that can run AppleScript) over the network: