Heh. (/me tips hat...)

Of course we already knew (from Langton's Ant) that the ruleset, suitably generalized to arbitrarily large arenas and arbitrarily long games, is Turing complete. The neat surprise isn't that 5 ants suffice, it's that time and space suffice to draw something iconic and recognizable. (At least when Sliding Miners don't come and slice it all up. ;))