Tolkien would turn in his grave, his masterwork a children's toy?!
Technically, Tolkien's 'masterwork' started out as a children's toy - he told
The Hobbit as a new kind of fairy tale to his own children at home.
As to LOTR...
..yes, it would have been utterly brilliant as a Lego line.
But I think it would have killed Castle as a Lego line. Why? Well, look at most of the great Castle stuff on Brickshelf. It's almost all improvised and created from peoples' personal collections from all different ranges of official sets. People have a limited amount of stuff to work with and so they have to be more thoughtful and creative in how they build. This usually produces higher quality MOCs as more thought and effort has gone into them. But if we had LOTR, almost everything would be taken for granted - if we needed an opening and closing gate most people wouldn't build their own but just take the official one out of the Hornburg set and use that. People who wanted to build monsters wouldn't need to try out other Lego themes for evil heads any more because the Uruk Hai heads would be instantly available. No-one would need to build their own dragon; they'd just use the Fellbeasts. Basically, most builders wouldn't build any more, they'd just assemble different LOTR parts.
Also, I think LOTR has had a positive influence anyway. The release of Fellowship of the Ring put focus back on swords and sorcery and knights and castles, and so gave the previously ailing Lego Castle theme a massive interest boost. It worked officially, too - we got KKII just after ROTK, and now the new 2007 Castle line, both of which are prety obviously modelled on LOTR. So I think things turned out fairly well.
- Matt