Many NoSQL proponents are endlessly gunning for the RDBMS, always counterpointing NoSQL solutions with the RDBMS, but then when confronted with specifics they throw their hands up and say "Different tools, man! Horses for courses!"
I'm not sure you're really paying attention to the real debate here.
Most of the people using non-relational data stores (for actual work) are employing it in tandem with traditional RDBMS solutions. And those that are feeding on a strictly NoSQL diet are usually just toying around or using Fisher-Price wrappered versions of NoSQL like App Engine's Datastore or Amazon's SimpleDB.
Maybe people who are using non-relational data stores for actual work are employing it in tandem with RDBMS but most talk is about completely replacing RDBMS with NoSQL. This latest round of fun started with Digg replacing MySQL with Cassandra. Even other HN comments on this very article don't talk about using it tandem with SQL; most would probably consider that a waste of the advantages of NoSQL.
I use non-relational solutions combined with a RDBMS solutions but that seems to put me on the other side of the debate.
I'm not sure you're really paying attention to the real debate here.