This thread is the best discussion of the Words of Powers on these boards.
I think the system needs to be a lot more generic. More specifically, the words should be as generic as possible. Basically, just "elemental damage of xD6," "moves objects with X strong force," "grants invisibility," and so on, so the players themselves can create the effects. With scaling as suggested by the OP, of course. There should also be less limitations on target/effect combination, such as the force word that only can be cast on personal (mimicking mage armor). I would like to see system be completely free, only limited by spell levels.
The system definitely has great potential of moving the game towards more inventive use of magic. It could also make magic feel more mysterious - D&D has always had a huge limitations in that magic is confined to predetermined "spells" instead of having a magical force alá Wheel of Time or even Lord of the Rings. There would also be less spell bloat inside this system; instead of coming up with a new spell for every possible situation there can just be introduced a few more words that increase player possibilities tenfold.
Basically, I think the words should be simpler and more generic. I am definitely in favor of 'condition' and 'duration' words for every spell. I'm not entirely sure how to accomplish it, but if the word system could somehow be innovatively grasped by players who would go on to smartly construct and adapt spells on the spot, it would be the greatest innovation D&D has ever seen.
