Version 3 has not been updated since 2007. Now there's a new beta for version 1 of iClock Pro, so I became intrigued. For my needs, it doesn't seem to add much compared to my current solutions.
In March, the price was $10. Now it's $20 and I can get a $5 discount. Once iClock is officially released, the price will be $30. Interesting pricing scheme, but I would not pay more than $5 or $10 to upgrade my old version.
When I began using iClock I don't think there were alternatives for the Mac. Today there's World Clock Deluxe, You Control, Menu Calendar Clock, Meridian, Time Palette, and more.