Sqlgreg, Yes it is quite useful ;-). Companies that have chosen to use Boomerang for all their notification needs i.e. email, fax, printing and twitter etc find Boomerang very effective, easy and yet flexible to use.
We might include Twitter In and Out in the standard edition sometime in the future as the framework progress in depth and width, but frankly I believe that the price is pretty modest for a robust SQL based integration to Twitter that can be used to implement corporate CRM, ERP or other business solutions.
As far as spam I have little concern since you have to authorize to connect to a Twitter account that you control with your instance of Boomerang. This Twitter process is difficult to manipulate. Twitter has also established some protection from spam through quotas - abusing users exceeding their account limits get suspended.
/Michael