While I do believe that Bo9S:ToB is the early incarnation of some of the 4E abilities I do not think they will replace spells as the magic system. Instead I believe they will be an aside to the spells. Keep in mind that they said Vancian spells are only "mostly" going away, and that these types of spells only make up about 20% of the caster's arsenal. I fully expect Fireball to still be a "Vancian" spell. At the same time however, I expect to see them have Bo9S:ToM style 'powers' (e.g. from something like the "Emerald Frost" discipline) that are their "per encounter" abilities. JMHO.