What about HP-UX SRP containers ?
Funny that the article doesn't mention HP-UX clusters on Itanium-based Integrity servers, be it simple ServiceGuard packages or SRP containers that are quite close to Sun (well, Oracle) Solaris containers.
If they're excluded from Oracle's "exception" to 1 machine = 1 license rule, then I know at least one big, big Oracle shop that's going to be in trouble.