My bet is that Blood Pulse will be updated to be "every square the target moves out of" -- thus not to be triggered by push and pull. I think the idea is exertion causes them harm, not that there is a damage zone they are moving through. Just a guess of course, but considering the idea of restricting their options is a lot more (4e) wizardly than trying to combo for uber damage, I feel pretty sure that's where they'll go.