@CodeSmith
You're absolutely right, you must not forget strong software auditing procedures even when the architecture is not x86.
However, the truth is that having other than x86 architechture limits the impact of found buffer overflows and automated worms/scripts/viruses.
Also most of the script kiddies (using exploit apps created by real hackers) are not familiar with PowerPC and are unable to root them with known buffer overflow (and in most cases the PPC instruction set limits the buffer overflow, for example it is very hard to embed PPC code to a null terminated string).
So IMO not being x86 can be seen as an additional value.
