Well, shift registers would have been the worst solution. Let's analyze what I did:
drive 80 LEDs through 8 phases. Each LED with a 1k resistor. If I would want to mass produce I could use some controller with 8 output pins plus internal RC oscillator. Actually even cheaper setup would do the trick.
If I wanted to use an Arduino this would still hold true.
However there are some points in favor of my current solution:
1) My blog is dedicated to the Blinkenlight Shield
2) I had 12 Blinkenlight Shields and 8 Arduinos lying around but no shift registers at hand.
3) The wiring for this setup is much simpler
4) It gives me the opportunity to fool around
