My personal take on this, if anyone cares, is so what? If the novels are good, than they will be worth buying. If they are poor, than they aren't, whether JMS approved the outline or not. Besides, the only two areas that I think that his oversight is essential to are the Telepath War and the resolution of Crusade, both of which JMS has indicated he will keep to himself for some future (and highly unlikely) project. Beyond that, I was underwhelmed by both LotR and the unpublished Crusade scripts, so I'm not exactly chomping at the bit to see him muck with his own canon that much more. Since I am also of the opinion that the Babylon 5 universe is effectively dead outside of game products and tie-in novels, I think that canon will take care of itself as it is unlikely that there will be much new super-duper official product anytime soon.
Most importantly to me, his Mongoose bashing was in extremely poor taste and innapropriate for a public forum. Sadly, this kind of arrogant lashing out has become commonplace from JMS and has really diminished my respect for the man.
Matt