> PPC is 20 years old now so the early patents will be expiring.
> Anything newer and you can expect IBM to send in a small army of lawyers.

IBM's Army of Lawyers against China's PLA. Interesting thought ;-) Seriously, you may be right that the expiration of IBM's related early patents is the reason that PWRSemi is only starting this endeavour now. But I'm not quite convinced that it isn't just due to them being located in China and thus out of reach of western jurisdiction ;-)