I have been using Calendock since 10.1.5 and now I'm on 1.4.2 and it still works great. All I wanted to show the calendar of the month I'm in this program does perfectly so I can go to the dock and show me the month and do some simple schedling with opening an calendar program with take a few seconds.
This shows how an simple program will work through a several major upgrades of the OS X series. However I don't think it will leap to the Intel platform unless there is a transition application or recomplie.