Honestly, from what Tom said, I think the odds of them appearing are much too high. Sure, it is unlikely that they all be used right now... but they are kind of like nuclear weapons. Once someone starts using them, I expect others will likely follow in. Apparently, the effects would be disastrous, though... it seems way too early for BT to see disastrous results again.
Erm...I'm not 100% sure that the analogy to nukes is intentional, but I suspect it is.
I
do know that the intention is that these scrolls are the engines that will drive the Next Invasion.
For that to happen, by the time they are finally used, there really needs to be a critical mass of them.
Based on what I know about the numbers of scrolls out there now, and about their actual effects, I think that it's right on track. (Note that I do not think it's there just yet.)
