fault-tolerant communication through shared memory?
If I read the article correctly, you described a fault-tolerant system in which duplicated processing elements communicate via a single shared memory. The shared memory architecture sounds like SMP to me, and is a single point of failure that renders the whole system non-fault tolerant. (Please correct me if I am wrong here.)
Also, I found the following sentence especially interesting:
The fault-tolerant gear usually makes it way to banks, stock exchanges, emergency call centers and the like.
Large banks, stock exchanges and emergency call centers already use real fault-tolerant gear: Tandem systems. Tandem is now a division of HP, and has always specialized in "shared-nothing", real fault tolerance. As for "and the like", AOL uses Tandems and the NSA uses Tandems, along with numerous other organizations that would rather buy a 747 instead of gluing a million pigeons together.